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Advances in selective conversion of carbohydrates into 5-hydroxymethylfurfural

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Green Energy & Environment 2024年第9期9卷 1384-1406页

作者： Jie Liang Jianchun Jiang Tingting Cai Chao Liu Jun Ye Xianhai zeng kui Wang Institute of Chemical Industry of Forest Products Chinese Academy of Forestry National Engineering Lab.for Biomass Chemical Utilization Co-Innovation Center of Efficient Processing and Utilization of Forest Resources Nanjing Forestry University College of Energy State Key Laboratory of Physical Chemistry of Solid Surfaces Xiamen University

Converting carbohydrates into 5-hydroxymethylfurfural(5-HMF) is an attractive and promising route for value-added utilization of agricultural and forestry biomass resource. As an important platform compound, 5-HMF possesses high active furan structure with hydroxymethyl and aldehyde group for production of various bio-chemicals and materials, meanwhile, which suffer from low stability and poor yield during the industrial biorefinery process. Hence, selective production of 5-HMF with high-yield and low-cost has attracted extensive attention from scientific and industrial researchers. This review sorted and described the latest advanced research on solvent and catalyst system, as well as energy field effect for production of 5-HMF with different feedstock in detail, emphatically discussing the solvent effect and its synergistic effect with other aspects. Besides, the future prospects and challenges for production of 5-HMF from carbohydrates were also presented, which provide a profound insight into industrial 5-HMF process with economic and environmental feature.

关键词： 5-Hydroxymethylfurfural Biorefinery Solvent Selectivity Carbohydrate

Effects of formal credit on pastoral household expense: Evidence from the Qinghai-Xizang Plateau of China

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Journal of Integrative Agriculture 2024年第5期23卷 1774-1785页

作者： Yan Zhang Yi Huang fan Zhang zeng Tang State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems College of Pastoral Agriculture Science and TechnologyLanzhou UniversityLanzhou 730020China

Formal credit is critical in agricultural production,allowing more expenditure and productive input,thereby improving farmers'*** pastoral China,formal financial institutions are gradually ***,a limited understanding remains of how formal credit affects herders'household *** on a survey of 544 herders from the Qinghai-Xizang Plateau of China,this study adopted the propensity score matching approach to identify the effect of formal credit on herders'total household expenses,daily expenses,and productive *** results found that average age,grassland mortgage,and other variables significantly affected herders'participation in formal *** credit could significantly improve household expenses,especially productive expenses.A heterogeneity analysis showed that formal credit had a greater impact on the household total expense for those at higher levels of wealth;however,it significantly affected the productive expense of herders at lower wealth ***,the mediating effect indicated that formal credit could affect herders'household income,thus influencing their household ***,this study suggests that policies should improve herders'accessibility to formal credit.

关键词： formal credit herders expense Qinghai-Xizang Plateau

Development of a novel Eu^(3+)-doped tantalate red-emitting phosphor for w-LEDs application

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Journal of Rare Earths 2024年第8期42卷 1479-1488,I0003页

作者： fan zeng Jingjing Ru Bing Zhao Feiyun Guo Jianzhong Chen College of Chemistry and Materials Fujian Province University Key Laboratory of Green Energy and Environment CatalysisNingde Normal University.Ningde352100China School of Environment and Resources School of Carbon Neutral and Modern IndustryFujian Normal UniversityFuzhou350007China College of Information and Mechanical&Electrical Engineering Ningde Normal UniversityNingde352100China College of Chemistry Fuzhou UniversityFuzhou350108China

Two novel phosphors LiBa_(4(1-x))Eu_(4x)Ta_(3)O_(12)(H-LBTO:xEu^(3+)) and Li_(0.25)Ba_(1-x)Eu_(x)Ta_(0.75)O_(3)(C-LBTO:xEu^(3+))were prepared successfully by a molten salt *** transformation between these two structures was realized by changing the sintering temperature or changing the Eu^(3+) ions concentration,which was also demonstrated by the X-ray diffraction(XRD),scanning electron microscopy(SEM),diffuse reflectance spectra(DRS),and photoluminescence excitation(PLE) analyses,Both the sintering temperature and the Eu^(3+)ions doping concentration have significant impact on the formation of the crystal *** these phosphors sintered at 1023 K exhibit two major luminescence lines at 594 and 614 nm under nearUV light of 395 nm excitation,corresponding to Eu^(3+)ions typical transitions of ^(5)D_(0)→^(7)F_(1) and ^(5)D_(0)→^(7)F_(2).The optimum concentration of Eu^(3+) ions is 9 mol% for C-LBTO:xEu^(3+) samples and the quenching interaction type is the nearest-neighbor ion *** thermal stability of the C-LBTO:0.09Eu^(3+)sample was investigated in detail and the device application further suggests that C-LBTO:0.09Eu^(3+) can be used as a red phosphor for near-UV excited w-LEDs in lighting.

关键词： Phosphor Tantalate LED device Rare earths

Unsupervised Multi-Expert Learning Model for Underwater Image Enhancement

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IEEE/CAA Journal of Automatica Sinica 2024年第3期11卷 708-722页

作者： Hongmin Liu Qi Zhang Yufan Hu Hui zeng Bin fan the School of Intelligence Science and Technology and the Institute of Artificial Intelligence University of Science and Technology BeijingBeijing 100083China the School of Automation and Electrical Engineering University of Science and Technology BeijingBeijing 100083China IEEE

Underwater image enhancement aims to restore a clean appearance and thus improves the quality of underwater degraded *** methods feed the whole image directly into the model for ***,they ignored that the R,G and B channels of underwater degraded images present varied degrees of degradation,due to the selective absorption for the *** address this issue,we propose an unsupervised multi-expert learning model by considering the enhancement of each color ***,an unsupervised architecture based on generative adversarial network is employed to alleviate the need for paired underwater *** on this,we design a generator,including a multi-expert encoder,a feature fusion module and a feature fusion-guided decoder,to generate the clear underwater ***,a multi-expert discriminator is proposed to verify the authenticity of the R,G and B channels,*** addition,content perceptual loss and edge loss are introduced into the loss function to further improve the content and details of the enhanced *** experiments on public datasets demonstrate that our method achieves more pleasing results in vision *** metrics(PSNR,SSIM,UIQM and UCIQE) evaluated on our enhanced images have been improved obviously.

关键词： Multi-expert learning underwater image enhancement unsupervised learning

A Study on the Performances of Solar Air Collectors Having a Hemispherical Dimple on the Absorber Plate

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Fluid Dynamics & Materials Processing 2024年第5期20卷 939-955页

作者： Shuilian Li fan zeng Xinli Wei School of Architecture and Environmental Engineering Zhengzhou Technical CollegeZhengzhou450121China School of Mechanical and Power Engineering Zhengzhou UniversityZhengzhou450001China

In order to increase the efficiency of solar air collectors,a new variant with a protrusion is proposed in this study,and its performances are analyzed from two points of view,namely,in terms of optics and thermodynamics *** comparing and analyzing the light paths of the protrusion and the dimple,it can be concluded that when sunlight shines on the dimple,it is reflected and absorbed multiple times,whereas for the sunlight shining on the protrusion,there is no secondary reflection or absorption of *** the lighting area and the properties of the surfaces are the same,the absorption rate of the dimple is 10.3 percentage points higher than that of the *** the range of Reynolds number from 3000 to 11000,numerical simulations about the effects of the relative height(e/Dh=0.033–0.1)and relative spacing(p/e=4.5–8.5)of protrusions on air heat transfer and flow resistance show that,in terms of comprehensive evaluation coefficient(PF),the best relative height is 0.085,when the relative spacing is 5.A correlation of Nu and f with Re,e/Dh and p/e is obtained by linear regression of the results,in order to provide a useful reference for the design and optimization of this kind of solar air collector.

关键词： Heat transfer hemispherical protrusion dimple solar air collector correlation

Social Radars: Finding Targets in Cyberspace for Cybersecurity

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IEEE/CAA Journal of Automatica Sinica 2024年第2期11卷 279-282页

作者： Lili fan Changxian zeng Yutong Wang Jiaqi Ma Fei-Yue Wang School of Information and Electronics Beijing Institute of TechnologyBeijing 100081China School of Science Dalian Minzu UniversityDalian 116600China State Key Laboratory for Management and Control of Complex Systems Institute of AutomationChinese Academy of SciencesBeijing 100190China Department of Civil and Environmental Engineering University of CaliforniaLos AngelesCA 90024 USA IEEE State Key Laboratory for Management and Control of Complex Systems Chinese Academy of SciencesBeijing 100190 Faculty of Innovation Engineering Macao University of Science and TechnologyMacao 999078China

INSPIRED by the insight from American political scientist Lasswell, who summarized the environmental role in societal surveillance [1], Schramm coined the term “social radar” [2] as it resembles the activities of radar in collecting and processing information, playing a crucial role in helping humans perceive changes in the internal and external environment and promptly adjusting adaptive behaviors.

关键词： prompt summarized insight

Type Synthesis of Self-Alignment Parallel Ankle Rehabilitation Robot with Suitable Passive Degrees of Freedom

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Chinese Journal of Mechanical Engineering 2024年第1期37卷 160-175页

作者： Ya Liu Wenjuan Lu Dabao fan Weijian Tan Bo Hu Daxing zeng School of Mechanical Engineering Yanshan UniversityQinhuangdao 066004China School of Mechanical Engineering Dongguan University of TechnologyDongguan 523808China Dongguan Engineering Technology Research Center for Parallel Robot Dongguan 523808China The DGUT Innovation Center of Robotics and Intelligent Equipment Dongguan 523808China

The current parallel ankle rehabilitation robot(ARR)suffers from the problem of difficult real-time alignment of the human-robot joint center of rotation,which may lead to secondary injuries to the *** study investigates type synthesis of a parallel self-alignment ankle rehabilitation robot(PSAARR)based on the kinematic characteristics of ankle joint rotation center drift from the perspective of introducing"suitable passive degrees of freedom(DOF)"with a suitable number and ***,the self-alignment principle of parallel ARR was proposed by deriving conditions for transforming a human-robot closed chain(HRCC)formed by an ARR and human body into a kinematic suitable constrained system and introducing conditions of"decoupled"and"less limb".Second,the relationship between the self-alignment principle and actuation wrenches(twists)of PSAARR was analyzed with the velocity Jacobian matrix as a"bridge".Subsequently,the type synthesis conditions of PSAARR were ***,a PSAARR synthesis method was proposed based on the screw theory and type of PSAARR synthesis ***,an HRCC kinematic model was established to verify the self-alignment capability of the *** this study,93 types of PSAARR limb structures were synthesized and the self-alignment capability of a human-robot joint axis was verified through kinematic analysis,which provides a theoretical basis for the design of such an ARR.

关键词： Ankle rehabilitation robot Self-alignment Parallel mechanism Type synthesis Screw theory

Advances in environmental DNA monitoring:standardization,automation,and emerging technologies in aquatic ecosystems

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Science China(Life Sciences) 2024年第7期67卷 1368-1384页

作者： Suxiang Lu Honghui zeng fan Xiong Meng Yao Shunping He State Key Laboratory of Freshwater Ecology and Biotechnology Institute of HydrobiologyChinese Academy of SciencesWuhan 430072China Institute of Ecology College of Urban and Environmental SciencesPeking UniversityBeijing 100871China School of Life Sciences Peking UniversityBeijing 100871China Institute of Deep Sea Science and Engineering Chinese Academy of SciencesSanyaChina Center for Excellence in Animal Evolution and Genetics Chinese Academy of SciencesKunmingChina

Environmental DNA(eDNA)monitoring,a rapidly advancing technique for assessing biodiversity and ecosystem health,offers a noninvasive approach for detecting and quantifying species from various environmental *** this review,a comprehensive overview of current eDNA collection and detection technologies is provided,emphasizing the necessity for standardization and automation in aquatic ecological ***,the intricacies of water bodies,from streams to the deep sea,and the associated challenges they pose for eDNA capture and analysis are *** paper delineates three primary eDNA survey methods,namely,bringing back water,bringing back filters,and bringing back data,each with specific advantages and constraints in terms of labor,transport,and data ***,innovations in eDNA sampling equipment,including autonomous drones,subsurface samplers,and in-situ filtration devices,and their applications in monitoring diverse taxa are ***,recent advancements in species-specific detection and eDNA metabarcoding are addressed,highlighting the integration of novel techniques such as CRISPR-Cas and nanopore sequencing that enable precise and rapid detection of *** implications of environmental RNA and epigenetic modifications are considered for future applications in providing nuanced ecological ***,the review stresses the critical role of standardization and automation in enhancing data consistency and comparability for robust long-term *** propose that the amalgamation of these technologies represents a paradigm shift in ecological monitoring,aligning with the urgent call for biodiversity conservation and sustainable management of aquatic ecosystems.

关键词： eDNA methodology sampler environment biomonitoring ecogenomic sensors ocean observation instrument

Modelling and simulation study on dynamic pollution accumulation process of composite insulator

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High Voltage 2024年第3期9卷 601-613页

作者： Zhongyi Yang Dongxiong Liu Xiangjun zeng Caijin fan Xin Yang Yafei Huang School of Electrical and Information Engineering Changsha University of Science and TechnologyChangshaChina State Key Laboratory of HVDC Electric Power Research InstituteCSGGuangzhouChina

With the widespread application of composite insulators in transmission lines,exploring the accumulation mechanism of pollution particles on composite insulator surfaces is of importance to ensure the safe and steady operation of the power *** the current theoretical shortcomings,this study categorises the accumulation process of particles on the insulator surface into three stages,namely‘spatial motion’,‘surface collision’,and‘surface motion’.The motion and rotation velocities in a multi-physics field are calculated in the spatial motion *** the surface collision stage,a parameter called‘neck height’is introduced to determine the optimum mechanics theory,and the normal deposition criterion is *** the surface motion stage,the sliding displacement and rolling displacement on the surface are calculated based on the rotation speed of the particles.A dynamic pollution accumulation model of the composite insulator is estab-lished based on the normal deposition criterion and tangential ***,numerical simulations are performed by using the finite element *** results show that the proposed model agrees with the actual insulator pollution accu-mulation,and the deposition model is still applicable for various types of composite insulators operating in different applied *** deposition probability of particles increases with the increasing particle *** the surface motion stage,particle displacement increases with particle size and wind velocity.

关键词： composite displacement dynamic