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A Study on the Impact of Chemical Structure on the Evolution of Aggregate Structure in Fiber-shaped High Density Polyethylene Vitrimer

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Chinese Journal of Polymer Science 2024年第10期42卷 1557-1565页

作者： Bing Wang Yuan-Chu Gao Hai Wang Hui niu State Key Laboratory of Fine Chemicals School of Chemical EngineeringDalian University of Technology

Vitrimers have emerged as a prominent research area in the field of polymer materials. Most of the studies have focused on synthesizing polymers with versatile dynamic crosslinking structures, while the impact of chemical structure on aggregate structure of vitrimers, particularly during polymer processing, remains insufficiently investigated. The present study employed commercial maleic anhydride-grafted-high density polyethylene (M-g-HDPE) as the matrix and hexanediol as the crosslinker to facilely obtain fiber-shaped HDPE vitrimers through a reaction extrusion and post-drawing process. Through chemical structure characterization, morphology observation, thermal and mechanical properties investigation, as well as aggregate structure analysis, this work revealed the influence of dynamic bonds on the formation of aggregate structures during fiber-shaped vitrimers processing. A small amount of dynamic bonds in HDPE restricts the motion of PE chain during melt-extruding and post-drawing, resulting in a lower orientation of the PE chains. However, lamellar growth and fibril formation during post-drawing at high temperature are enhanced to some extent due to the competition between dynamic bond and chain relaxation. The uneven morphology of fibershaped HDPE vitrimers can be attributed to the stronger elastic effect brought by dynamic bonding, which plays a more dominant role in determining the mechanical properties of fiber-shaped vitrimers compared to aggregate *** Vitrimers have emerged as a prominent research area in the field of polymer *** of the studies have focused on synthesizing polymers with versatile dynamic crosslinking structures,while the impact of chemical structure on aggregate structure of vitrimers,particularly during polymer processing,remains insufficiently *** present study employed commercial maleic anhydride-grafted-high density polyethylene (M-g-HDPE) as the matrix and hexanediol as the crosslinker to facile

关键词： Aggregate structures Fiber-shaped High density polyethylene vitrimer Transesterification reaction

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Peptide drugs: a new direction in cancer immunotherapy

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Cancer Biology & Medicine 2024年第3期21卷 198-203页

作者： Xinghua Sui Xiaoshuang niu Xiuman Zhou Yanfeng Gao School of Pharmaceutical Sciences(Shenzhen) Shenzhen Campus of Sun Yat-sen UniversityShenzhen 518107China

Cancer immunotherapy has emerged as a promising approach in cancer treatment and is considered a major advancement after surgical interventions, radiotherapy, chemotherapy, and targeted therapy. The clinical use of im... 详细信息

关键词： drugs immunotherapy cancer

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Sliding behaviors of the trapezoidal roof rock block under a lateral dynamic disturbance

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第3期16卷 741-760页

作者： Feng Dai Wancheng Zhu Min Ren Shunchuan Wu Leilei niu Faculty of Land Resources Engineering Kunming University of Science and TechnologyKunming650093China Center for Rock Instability and Seismicity Research Department of Mining EngineeringSchool of Resource and Civil EngineeringNortheastern UniversityShenyang110819China

The surrounding rock of underground space is always affected by external dynamic disturbance from the side position,such as blasting vibration from a stope at the same level or seismic waves from adjacent strata.A series of laboratory tests,numerical simulations and theoretical analyses were carried out in this study to disclose the sliding mechanism of roof rock blocks under lateral ***,the experiments on trapezoidal key block under various clamping loads and disturbance were conducted,followed by numerical simulations using the fast Lagrangian analysis of continua(FLAC3D).Then,based on the conventional wave propagation model and the classical shear-slip constitutive model,a theoretical model was proposed to capture the relative displacement between blocks and the sliding displacement of the key *** results indicate that the sliding displacement of the key block increased linearly with the disturbance energy and decreased exponentially with the clamping load when the key block was disturbed to slide(without instability).Meanwhile,when the key block was disturbed to fall,two types of instability process may appear as immediate type or delayed *** addition,the propagation of stress waves in the block system exhibited obvious low-velocity and lowfrequency characteristics,resulting in the friction reduction effect appearing at the contact interface,which is the essential reason for the sliding of rock *** results can be applied to practical underground engineering and provide valuable guidance for the early detection and prevention of rockfalling disasters.

关键词： Lateral dynamic disturbance Trapezoidal rock block system Low-velocity and low-frequency wave Friction reduction effect Instability mode

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Sustainable Intensification and Large-scale Operation of Cultivated Land Use at the Farmers’ Scale:A Case Study of Shandong Province,China

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Chinese Geographical Science 2024年第1期34卷 149-167页

作者： LI Li LYU Xiao ZHANG Anlu niu Shandong PENG Wenlong School of Public Administration Huazhong Agricultural UniversityWuhan430070China Department of Geography University of ZurichZurich8057Switzerland School of Humanities and Law Northeastern UniversityShenyang110169China School of Geography and Tourism Qufu Normal UniversityRizhao276800China

Sustainable intensification of cultivated land use(SICLU) and large-scale operations(LSO) are widely acknowledged strategies for enhancing agricultural ***,the existing literature has faced challenges in precisely defining SICLU and constructing comprehensive indicators,which has hindered the exploration of factors influencing LSO within the SICLU *** address this gap,we integrated self-efficacy theory into the design of an index framework for evaluating *** subsequently employed econometric models to analyze the significant factors that impact *** findings reveal that SICLU can be divided into four key dimensions:intensive management,efficient output,resource conservation,and ecological environment ***,it is crucial to incorporate belief-based cognitive factors into the index system,as farmers’ understanding of fertilizer and pesticide application significantly influences their willingness to engage in ***,we identify grain market turnover as the most influential factor in promoting LSO,with single-factor contribution rates reaching 70.9% for cultivated land transfer willingness and 62.5% for the total planting ***,unlike irrigation and agricultural machinery inputs,increased labor inputs correspond to larger planting areas for *** trend may be attributed to reduced labor availability because of rural labor migration,whereas the reduction in irrigation and agricultural input is contingent on innovations in production practices and the transfer of cultivated land management ***,SICLU dynamically influences LSO,with each index related to SICLU having an optimal range that fosters *** insights offer valuable guidance for policymakers,emphasizing farmers as their central focus,with the adjustment of input and output factors as a means to achieve LSO as the ultimate *** conclusion,we propose research avenues for further enriching the SICLU framework to ensur

关键词： sustainable intensification of cultivated land use(SICLU) self-efficacy status quo bias input and output Boosted Regression Tree willingness to transfer cultivated land cultivated land planting areas Shandong,China

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Spatial Differentiation and Convergence Trend of High-quality Development Level of China’s Tourism Economy

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Chinese Geographical Science 2024年第2期34卷 230-249页

作者： CAO Shanshan HE Zhaoli niu Jinlan WANG Songmao ZHAO Lei School of Geography and Ocean Science Nanjing UniversityNanjing 210046China School of Business Administration Nanjing University of Finance and EconomicsNanjing 210046China School of Economics and Management Shandong Agricultural Uni-versityTai’an 271018China School of Hotel Management Shanghai Business SchoolShanghai 201400China School of Man-agement Zhejiang University of TechnologyHangzhou 310014China

This paper aims to interpret the connotation of high-quality development of tourism economy(HQTE)from the perspective of the new development concepts of innovation,coordination,green,openness and sharing,and then to evaluate the spatial differenti-ation of China’s HQTE based on provincial panel data from 2009 to ***,we employ the spatial convergence model to ex-plore the absolute and conditionalβconvergence trends of HQTE in the whole country and the eastern,central and western regions of *** empirical results reveal that:1)within the decade,from 2009 to 2018,regions of China with the highest HQTE index is its eastern region followed by the central region and then the western region,but the fastest growing one is the western region of China fol-lowed by the central region and then the eastern region.2)Whether or not the spatial effect is included,there are absolute and condition-alβconvergence in HQTE in the whole country and aforementioned three regions.3)The degree of government attention as well as the level of economic development and location accessibility are the positive driving factors for the convergence of HQTE in the whole country and the three *** degree of marketization and human capital have not passed the significance test either in the whole country or in the three *** above conclusions could deepen the understanding of the regional imbalance and spatial conver-gence characteristics of HQTE,clarify the primary development objects,and accomplish the goal of China’s HQTE.

关键词： new development concepts high-quality development of tourism economy(HQTE) spatial convergence China

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Characterization of Domeless receptors and the role of Bd Domeless3 in anti-symbiont-like virus defense in Bactrocera dorsalis

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Journal of Integrative Agriculture 2024年第4期23卷 1274-1284页

作者： Wei Zhang Shaoyang Li Rong Li Jinzhi niu Jinjun Wang Key Laboratory of Entomology and Pest Control Engineering College of Plant ProtectionSouthwest UniversityChongqing 400715China Key Laboratory of Agricultural Biosafety and Green Production of Upper Yangtze River Ministry of Education/International Joint Laboratory of China-Belgium on Sustainable Crop Pest ControlAcademy of Agricultural SciencesSouthwest UniversityChongqing 400715China

The Janus kinase/signal transducers and activators of transcription(JAK/STAT)signaling pathway play a pivotal role in innate *** invertebrates,Domeless receptors serve as the key upstream regulators of this *** our study on Bactrocera dorsalis,we identified three cytokine receptors:BdDomeless1,BdDomeless2,and *** receptor encompasses five fibronectin-type-III-like(FN III)extracellular domains and a transmembrane ***,these receptors exhibit the increased responsiveness to diverse pathogenic ***,only BdDomeless3 is upregulated during symbiont-like viral ***,silencing BdDomeless3 enhanced the infectivity of Bactrocera dorsalis cripavirus(BdCV)and *** picorna-like virus(BdPLV),underscoring BdDomeless3’s crucial role in antiviral defense of *** the suppression of Domeless3 expression,six antimicrobial peptide genes displayed decreased expression,potentially correlating with the rise in viral *** our knowledge,this is the first study identifying cytokine receptors associated with the JAK/STAT pathway in tephritid flies,shedding light on the immune mechanisms of ***.

关键词： Bactrocera dorsalis JAK/STAT pathway Domeless receptors antiviral immunity symbiont-like virus

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Breeding exceptionally fragrant soybeans for soy milk with strong aroma

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Journal of Integrative Plant Biology 2024年第4期66卷 642-644页

作者： Hongtao Xie Minglei Song Xuesong Cao Qingfeng niu Jianhua Zhu Shasha Li Xin Wang Xiaomu niu Jian-Kang Zhu Bellagen Biotechnology Co.Ltd. Jinan 250000China Institute of Advanced Biotechnology and School of Life Sciences Southern University of Science and TechnologyShenzhen 518055China School of Life Sciences Anhui Agricultural UniversityHefei 230036China Shandong Normal University Jinan 250000China

Soybean(Glycine max(L.)Merr.)is a major source of vegetable protein and oil in human diet and animal *** seeds have been extensively used in various food products and *** quality,particularly the aroma,affects cooking and eating,and ultimately influences consumer *** milk is particularly popular in China and has been gaining popularity in many other countries in the world.

关键词： exceptional soybean cooking

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An advanced 2D/3D g-C_(3)N_(4)/TiO_(2)@MnO_(2) multifunctional membrane for sunlight-driven sustainable water purification

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Nano Research 2024年第4期17卷 2368-2380页

作者： Fan Yu Chunjia Luo Xiaohan niu Min Chao Pengfei Zhang Luke Yan Polymer Materials&Engineering Department School of Materials Science&EngineeringChang’an UniversityXi’an 710064China Key Laboratory of Road Construction Technology and Equipment MOEChang’an UniversityXi’an 710064China School of Textile Science and Engineering Xi’an Polytechnic UniversityXi’an 710064China

Graphitic carbon nitride(g-C_(3)N_(4))nanosheets have attracted widespread interest in the construction of advanced separation ***,dense stacking and a single functionality have limited the membrane ***,an advanced two-/three-dimensional(2D/3D)g-C_(3)N_(4)/TiO_(2)@MnO_(2) membrane is constructed by intercalating 3D TiO_(2)@MnO_(2) nanostructures into g-C_(3)N_(4) *** 3D flower-like nanostructures broaden the transport channels of the composite *** membrane can effectively separate five oil-in-water(O/W)emulsions,with a maximum flux of 3265.67±15.01 L·m^(-2)·h^(-1)·bar^(-1) and a maximum efficiency of 99.69%±0.45%for toluene-in-water emulsion(T/W).Meanwhile,the TiO_(2)@MnO_(2) acts as an excellent electron acceptor and provides positive spatial separation of electrons–holes(e^(-)–h^(+)).The formation of 2D/3D heterojunctions allows the material with wider light absorption and smaller bandgap(2.10 eV).These photoelectric properties give the membrane good degradation of three different pollutants,with about 100%degradation for methylene blue(MB)and malachite green(MG).The photocatalytic antibacterial efficiency of the membrane is also about 100%.After cyclic experiment,the membrane maintains its original separation and photocatalytic *** remarkable multifunctional and self-cleaning properties of the g-C_(3)N_(4) based membrane represent its potential value for complex wastewater treatment.

关键词： graphitic carbon nitride(g-C_(3)N_(4))based membrane three-dimensional(3D)nanostructures self-cleaning multifunction

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Numerical and theoretical study of load transfer behavior during cascading pillar failure

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第8期16卷 3014-3033页

作者： Hangyu Dong Wancheng Zhu Leilei niu Chen Hou Xige Liu College of Geosciences and Engineering North China University of Water Resources and Electric PowerZhengzhou450046China Center for Rock Instability and Seismicity Research School of Resource and Civil EngineeringNortheastern UniversityShenyang110819China

To further study the load transfer mechanism of roofemulti-pillarefloor system during cascading pillar failure(CPF),numerical simulation and theoretical analysis were carried out to study the three CPF modes according to the previous experimental study on treble-pillar specimens,*** failure mode(SFM),domino failure mode(DFM)and compound failure mode(CFM).Based on the finite element code rock failure process analysis(RFPA^(2D)),numerical models of treble-pillar specimen with different mechanical properties were established to reproduce and verify the experimental results of the three CPF *** results show that the elastic rebound of roofefloor system induced by pillar instability causes dynamic disturbance to adjacent pillars,resulting in sudden load increases and sudden jump displacement of adjacent *** phenomena of load transfer in the roofemulti-pillarefloor system,as well as the induced accelerated damage behavior in adjacent pillars,were discovered and *** addition,based on the catastrophe theory and the proposed mechanical model of treble-pillar specimen edisc spring group system,a potential function that characterizes the evolution characteristics of roof emulti-pillarefloor system was *** analytical expressions of sudden jump and energy release of treble-pillar specimenedisc spring group system of the three CPF modes were derived according to the potential *** numerical and theoretical results show good agreement with the experimental *** study further reveals the physical essence of load transfer during CPF of roof emulti-pillarefloor system,which provides references for mine design,construction and disaster prevention.

关键词： Cascading pillar failure(CPF) Load transfer Multi-pillar Numerical simulation

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Numerical and experimental research on axial injection end-burning hybrid rocket motors with polyethylene fuel

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Chinese Journal of Aeronautics 2024年第8期37卷 91-105页

作者： Xiangyu MENG Hui TIAN Lingfei HE Jingfei GAO Xiaoting niu Guobiao CAI School of Astronautics Beihang UniversityBeijing 100191China Key Laboratory of Spacecraft Design Optimization&Dynamic Simulation Technologies Ministry of EducationBeijing 100816China

This study investigates the end-burning hybrid rocket motors with polyethylene fuel by the numerical simulation and *** on computational fluid dynamics,a numerical model is *** model is validated by two firing tests in this hybrid rocket motor,which uses oxygen and polyethylene as *** results show that the numerical and experimental data are in good agreement,and the error of the chamber pressure is less than 2.63%.Based on the simulation mode,the blowoff limit of the end-burning hybrid rocket motors is *** the nozzle throat diameter and the inner diameter of grain are large,it is more difficult for the hybrid rocket motor to achieve end-burning mode,i.e.,the flame spreading is prevented in the narrow *** main reason is that when the nozzle throat and the grain port are large,chamber pressure and oxidizer flow velocity are ***,the friction velocity considering the pressure and flow velocity is *** critical friction velocity is about 4.054–4.890 m/s in the hybrid rocket *** the friction velocity exceeds the critical friction velocity,the combustion mode in hybrid rocket motors changes from the flame spreading mode to the end-burning ***,the regression rate formula is obtained by fitting,which shows that the regression rate has a good correlation with combustion chamber *** critical friction velocity and regression rate formula can provide an important reference for end-burning hybrid rocket motors.

关键词： Hybrid rocket motor End burning Blowoff limit Flame propagation Regression rate

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