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ANovel Non-Isolated Cubic DC-DC Converter with High Voltage Gain for Renewable Energy Power Generation System

Energy Engineering 2024年第1期121卷 221-241页

作者： qin yao Yida Zeng qingui Jia School of Electrical Engineering Southwest Jiaotong UniversityChengdu610036China

In recent years,switched inductor(SL)technology,switched capacitor(SC)technology,and switched inductor-capacitor(SL-SC)technology have been widely applied to optimize and improve DC-DC boost converters,which can effectively enhance voltage gain and reduce device stress.To address the issue of low output voltage in current renewable energy power generation systems,this study proposes a novel non-isolated cubic high-gain DC-DC converter based on the traditional quadratic DC-DC boost converter by incorporating a SC and a SL-SC unit.Firstly,the proposed converter’s details are elaborated,including its topology structure,operating mode,voltage gain,device stress,and power loss.Subsequently,a comparative analysis is conducted on the voltage gain and device stress between the proposed converter and other high-gain converters.Then,a closed-loop simulation system is constructed to obtain simulation waveforms of various devices and explore the dynamic performance.Finally,an experimental prototype is built,experimental waveforms are obtained,and the experimental dynamic performance and conversion efficiency are analyzed.The theoretical analysis’s correctness is verified through simulation and experimental results.The proposed converter has advantages such as high voltage gain,low device stress,high conversion efficiency,simple control,and wide input voltage range,achieving a good balance between voltage gain,device stress,and power loss.The proposed converter is well-suited for renewable energy systems and holds theoretical significance and practical value in renewable energy applications.It provides an effective solution to the issue of low output voltage in renewable energy power generation systems.

关键词： Cubic DC-DC converter high voltage gain low device stress high efficiency renewable energy

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Synergically regulated silver species and surface oxygen on manganese oxide for promoted activity of formaldehyde oxidation

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Journal of Environmental Sciences 2024年第4期138卷 709-718页

作者： Shuo Hu Jianghao Zhang Xueyan Chen Xiaoxiao qin Jinshui yao Changbin Zhang School of Materials Science&Engineering Qilu University of Technology(Shandong Academy of Sciences)Jinan 250353China State Key Joint Laboratory of Environment Simulation and Pollution Control Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China University of Chinese Academy of Sciences Beijing 100049China

Formaldehyde(HCHO)is a common indoor pollutant that is detrimental to human health.Its efficient removal has become an urgent demand to reduce the public health risk.In this work,Ag-MnO_(x)-based catalysts were prepared and activated under different atmosphere(i.e.,air,hydrogen(H_(2))and carbon monoxide(CO))for efficient oxidation of HCHO.The catalyst activated with CO(Ag/Mn-CO)displayed the highest activity among the tested samples with 90% conversion at 100℃ under a gas space velocity of 75,000 mL/(g_(cat)·hr).Complementary characterizations demonstrate that CO reduction treatment resulted in synergically regulated content of surface oxygen on support to adsorb/activate HCHO and size of Ag particle to dissociate oxygen to oxidize the adsorbed HCHO.In contrast,other catalysts lack for either abundant surface oxygen species or metallic silver with the appropriate particle size,so that the integrate activity is limited by one specific reaction step.This study contributes to elucidating the mechanisms regulating the oxidation activity of Ag-based catalysts.

关键词： HCHO oxidation Ag-MnO_(x)-based catalyst Activation condition Synergic regulation Surface oxygen Oxidized Ag

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Evaluation of the intracellular lipid-lowering effect of polyphenols extract from highland barley in HepG2 cells

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Food Science and Human Wellness 2024年第1期13卷 454-461页

作者： Yijun yao Zhifang Li Bowen qin Xingrong Ju Lifeng Wang College of Food Science and Engineering/Collaborative Innovation Centre for Modern Grain Circulation and Safety Nanjing University of Finance and EconomicsNanjing 210023China

Active ingredients from highland barley have received considerable attention as natural products for developing treatments and dietary supplements against obesity.In practical application,the research of food combinations is more significant than a specific food component.This study investigated the lipid-lowering effect of highland barley polyphenols via lipase assay in vitro and HepG2 cells induced by oleic acid(OA).Five indexes,triglyceride(TG),total cholesterol(T-CHO),low density lipoprotein-cholesterol(LDL-C),aspartate aminotransferase(AST),and alanine aminotransferase(ALT),were used to evaluate the lipidlowering effect of highland barley extract.We also preliminary studied the lipid-lowering mechanism by Realtime fluorescent quantitative polymerase chain reaction(q PCR).The results indicated that highland barley extract contains many components with lipid-lowering effects,such as hyperoside and scoparone.In vitro,the lipase assay showed an 18.4%lipase inhibition rate when the additive contents of highland barley extract were 100μg/m L.The intracellular lipid-lowering effect of highland barley extract was examined using 0.25 mmol/L OA-induced HepG2 cells.The results showed that intracellular TG,LDL-C,and T-CHO content decreased by 34.4%,51.2%,and 18.4%,respectively.ALT and AST decreased by 51.6%and 20.7%compared with the untreated hyperlipidemic HepG2 cells.q PCR results showed that highland barley polyphenols could up-regulation the expression of lipid metabolism-related genes such as PPARγand Fabp4.

关键词： Highland barley Polyphenols extract Lipid-lowering effect HepG2 cells

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The stance and factors of international organizations towards countries from a Chinese perspective

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Data Intelligence 2024年第1期6卷 158-182页

作者： qin Zhang Haili Xue yaotian Wang yao Wang Ziqin Zhang qinghua qin Haoguang Liang National Science Library Chinese Academy of Sciences100190China China Center for Modernization Research 100190China Beijing International Studies University 100024China Beijing Key Laboratory of National Belt and Road Data Analysis and Decision Support 100024China University College London WC1E 6BTUK

The degree and scope of constraints imposed by International Organizations(IOs)on States are increasing,and identifying the factors affecting the IOs’stances on States is helpful to enhance the state's discourse power and influence in the international community.First,by coding the records of Regular Press Conferences of the Speaking Office of the Chinese Ministry of Foreign Affairs during the period of 20182022,we obtained a dataset of IOs’stances on China-related events.Second,we constructed political relation,economic relation,and humanistic relation indicators to complement the influence factors,adopted the Bayesian logit model,and applied the Monte Carlo Markov chain algorithm and Gibbs sampling to analyze the probability of IOs’positive stances towards China.The result shows that IOs’category,length of establishment,functional position,and relationship with China are all related to their tendency of making a statement about China.In terms of the heterogeneity of event types,forum-type IOs are significantly inclined to give positive assessment compared to service-type IOs on events focusing on China's own development.Further analysis reveals that the model for analyzing and predicting the attitudes of IOs is more effective when the international situation is in a stable period.

关键词： Bayesian Logit Model IOs' stances Attitude analysis Monte Carlo Markov chain International relation indicator

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Study of loess ecological slope protection optimization measures and prediction of the erosion control effect

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Journal of Geographical Sciences 2024年第6期34卷 1083-1108页

作者： ZHANG Xiaochao LI Mingli yao Zhongshao qin Liang MENG Minghui State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Chengdu University of TechnologyChengdu 610059China Sichuan Geological Environment Survey and Research Center Chengdu 610084China Sichuan Huadi Building Engineering Co. Ltd.Chengdu 610084China Sichuan Province Engineering Technology Research Center of Geohazard Prevention Chengdu 610084China

The large-scale management of ditches and implementation of land projects in loess areas have increased the arable land area but have caused considerable engineering issues, resulting in severe soil erosion. In this study, field tests were performed at different time scales, a control group was established, organic material–plant joint restoration technology was proposed as an optimized management measure, and the erosion control mechanism and restoration mode of organic material–plant joint restoration technology were analyzed. Based on the obtained experimental data, a Water Erosion Prediction Project(WEPP)-based hydraulic erosion model was constructed, sensitivity parameters were calibrated, and the soil erosion intensity and corresponding spatial distribution in the watershed of the study area were simulated via the geo-spatial interface for WEPP(GeoWEPP) after organic material–plant joint restoration technology was adopted to predict the effect of optimized management measures. The results showed that among the slopes with different restoration measures, organic material–plant joint restoration technology effectively controlled loess slope erosion, and the average erosion modulus of the organic material–grass and shrub transplantation slope reached only 23.37 t/km2, which is a decrease of 97.68% relative to the traditional grass–shrub protection slope. Moreover, the sand content of the joint restoration slope was reduced by 392.41 g/L relative to the bare slope, reaching only 0.29 g/L, and the runoff yield was reduced by 8.88 L/min. The GeoWEPP modeling results revealed that the total runoff yield and average annual erosion modulus of the watershed were lower after joint restoration than during the prerestoration period. Similarly, the total runoff yield of the watershed was 4.6%, the simulated 10-year average annual total sand production reached 2048.3 t,and the average annual erosion modulus was 582.75 t/km2, which is 52.15% lower than that under untreated conditions. This study provides a new strategy for

关键词： loess excavation slope slope surface erosion prevention and control measures GeoWEPP model erosion prediction

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Characterizing the behavior of surge-type glaciers in the Puruogangri Ice Field, Tibetan Plateau

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Journal of Geographical Sciences 2024年第6期34卷 1174-1194页

作者： ZHOU Sugang WANG Ninglian LI Zhijie yao Xiaojun ZHANG Yuje qin Gexia Shaanxi Key Laboratory of Earth Surface System and Environmental Carrying Capacity College of Urban and Environmental SciencesNorthwest UniversityXi'an 710127China Institute of Earth Surface System and Hazards College of Urban and Environmental SciencesNorthwest UniversityXi'an 710127China College of Geography and Environmental Science Northwest Normal UniversityLanzhou 730070China

The Puruogangri Ice Field(PIF), classified as an ultra-continental glacier, is considered extremely stable. However, several glaciers in this area have recently experienced surge events with significant instability and information on surge-type glaciers(STGs) in this region remains scarce. In this study, we identified six STGs and reported the observed characteristics of their surging behavior in the region by mapping glacier boundaries, surface flow velocity information, and glacier surface elevation changes using recent Landsat satellite imagery and shuttle radar topography mission(SRTM), TanDEM, and ASTER digital elevation model(AST14DEM) data. These data provide valuable insights into recent glacial processes, flow instability, and rapid glacial movement. During the active phase of the glaciers,all exhibited frontal advances and changes in surface elevation. Owing to limitations in the satellite imagery, flow velocity profiles were only available for glaciers N1(G089071E33998N),NE1(G089128E33943N), and SE3(G089278E33913N) during the active phase. However,these results effectively reflect the velocity variations in both glaciers before, during, and after the surge. Based on the characteristics of the STG, scientific expeditions, and meteorological data, we believe that the surge in PIF was largely influenced by glacier meltwater and changes in subglacial drainage systems.

关键词： glacier surge glacier surface elevation changes glacier surface velocity Puruogangri Ice Field

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An investigation on topologies of hybrid manifold,impinging-jet nozzle and micro-pin-fin heat sinks

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Science China(Technological Sciences) 2024年第4期67卷 1061-1076页

作者： SHI QianLei yao XiaoLe LIU Qian qin Le JU Xing XU Chao Key Laboratory of Power Station Energy Transfer Conversion and System of MOE North China Electric Power UniversityBeijing 102206China

The hybrid manifold micro-pin-fin(MMPF)heat sink combined nozzle jets is an option for large-scale integrated circuits(LSI).The demond for uniform and ultra-high heat flux removal by MMPF heat sink has not been adequately investigated.This work aims to solve the problem of fluid organization.The proposed basic tiling topologies,including square,regular hexagon,30°rhombus,and 60°rhombus topologies,provide different organized fluid flows and heat transfer patterns.The present study focuses on comparing these topologies according to independent porous medium parameters,such as nozzle pore size D_(Z),flow pore size D_(X,Y),and porosityε.The results show that the square topology achieves the smallest total thermal resistance R_(tot)value of0.0975×10^(-4)K m^2/W,while the hexagon topology achieved the highest value of COP/?T,which was 2033.9 K^(-1).According to the sensitivity analysis results,the optimal total thermal resistance can be obtained by balancing the influences of nozzle pore size,flow pore size,and porosity.The optimal pressure drop can be obtained by maximizing the porosity.

关键词： heat sink ultra-high heat flux manifold micro-pin-fin impinging-jet topology

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High-speed flexible near-infrared organic photodiode for optical communication

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National Science Review 2024年第3期11卷 227-238页

作者： Yu Zhu Hongbin Chen Ruiman Han Hao qin Zhaoyang yao Hang Liu Yanfeng Ma Xiangjian Wan Guanghui Li Yongsheng Chen The Centre of Nanoscale Science and Technology and Key Laboratory of Functional Polymer Materials Institute of Polymer ChemistryTianjin Key Laboratory of Functional Polymer Materials College of Chemistry and Renewable Energy Conversion and Storage Center(RECAST) Nankai University State Key Laboratory of Elemento-Organic Chemistry Nankai University

Optical communication is a particularly compelling technology for tackling the speed and capacity bottlenecks in data communication in modern society. Currently, the silicon photodetector plays a dominant role in high-speed optical communication across the visible-near-infrared spectrum. However, its intrinsic rigid structure, high working bias and low responsivity essentially limit its application in next-generation flexible optoelectronic devices. Herein, we report a narrow-bandgap non-fullerene acceptor（NFA） with a remarkable π-extension in the direction of both central and end units（CH17） with respect to the Y6 series, which demonstrates a more effective and compact 3D molecular packing, leading to lower trap states and energetic disorders in the photoactive film. Consequently, the optimized solution-processed organic photodetector（OPD） with CH17 exhibits a remarkable response time of 91 ns（λ = 880 nm） due to the high charge mobility and low parasitic capacitance, exceeding the values of most commercial Si photodiodes and all NFA-based OPDs operating in self-powered mode. More significantly, the flexible OPD exhibits negligible performance attenuation（<1%） after bending for 500 cycles, and maintains 96% of its initial performance even after 550 h of indoor exposure. Furthermore, the high-speed OPD demonstrates a high data transmission rate of 80 MHz with a bit error rate of 3.5 × 10-4, meaning it has great potential in next-generation high-speed flexible optical communication systems.

关键词： flexible organic photodetector high-speed NIR organic photodetector optical communication light fidelity narrow-bandgap non-fullerene acceptors

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A preliminary study on life history of marine red alga Stylonema alsidii(Zandardini)Drew f.ramosum Zheng et Li

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Journal of Oceanology and Limnology 2024年第3期42卷 915-922页

作者： Bingxin HUANG yao ZHANG Yue CHU Youxuan GUO Junxia LIANG Jianan qin Lanping DING Tianjin Key Laboratory of Animal and Plant Resistance College of Life SciencesTianjin Normal UniversityTianjin 300387China

Stylonema alsidii(Zandardini)Drew f.ramosum Zheng et Li is a common species in the genus Stylonema,but there are limited reports on morphological taxonomy and a lack of studies on life history and the regulation of early development.The early development,discoid formation,and erect thallus growth of Stylonema alsidii f.ramosum were observed under laboratory conditions.In addition,the influence of main environmental factors such as temperature and light intensity on its development was briefly studied,and various stages of its life history were observed.The result shows:(1)there are two reproductive modes:asexual reproduction and sexual reproduction;(2)the morphology of this species varies in different degrees under laboratory culture conditions;(3)sexual reproduction and asexual reproduction can coexist under suitable conditions.Five pathways of life history were inferred from experimental phenomena.Mature sporophytes form mature gametophytes by producing initially isolated or initially attached monospore,and mature gametophytes form mature sporophytes by fertilization of eggs and sperms.The sexual and asexual reproduction processes of Stylonema alsidii f.ramosum were reported for the first time,and this is also the first report on sexual reproduction in the genus Stylonema.

关键词： Stylonema alsidii(Zandardini)Drew f.ramosum Zheng et Li life history environmental factor asexual reproduction sexual reproduction

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Pillar effect induced by ultrahigh phosphorous/nitrogen doping enables graphene/MXene film with excellent cycling stability for alkali metal ion storage

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Journal of Energy Chemistry 2024年第6期93卷 146-156,I0004页

作者： Meng qin Yiwei yao Junjie Mao Chi Chen Kai Zhu Guiling Wang Dianxue Cao Jun Yan Key Laboratory of Superlight Materials and Surface Technology Ministry of EducationCollege of Materials Science and Chemical EngineeringHarbin Engineering UniversityHarbin 150001HeilongjiangChina Xiamen Key Laboratory of Rare Earth Photoelectric Functional Materials and Xiamen Institute of Rare Earth MaterialsHaixi InstituteChinese Academy of SciencesXiamen 361021FujianChina

Graphene's large theoretical surface area and high conductivity make it an attractive anode material for potassium-ion batteries(PIBs).However,its practical application is hindered by small interlayer distance and long ion transfer distance.Herein,this paper aims to address the issue by introducing MXene through a simple and scalable method for assembling graphene and realizing ultrahigh P doping content.The findings reveal that MXene and P-C bonds have a "pillar effect" on the structure of graphene,and the P-C bond plays a primary role.In addition,N/P co-doping introduces abundant defects,providing more active sites for K^(+) storage and facilitating K^(+) adsorption.As expected,the developed ultrahigh phosphorous/nitrogen co-doped flexible reduced graphene oxide/MXene(NPrGM) electrode exhibits remarkable reversible discharge capacity(554 mA hg^(-1) at 0.05 A g^(-1)),impressive rate capability(178 mA h g^(-1) at 2 A g^(-1)),and robust cyclic stability(0.0005% decay per cycle after 10,000 cycles at 2 A g^(-1)).Furthermore,the assembled activated carbon‖NPrGM potassium-ion hybrid capacitor(PIHC) can deliver an impressive energy density of 131 W h kg^(-1) and stable cycling performance with 98.1% capacitance retention after5000 cycles at 1 A g^(-1).Such a new strategy will effectively promote the practical application of graphene materials in PIBs/PIHCs and open new avenues for the scalable development of flexible films based on two-dimensional materials for potential applications in energy storage,thermal interface,and electromagnetic shielding.

关键词： Graphene MXene Phosphorous doping Pillar effect Potassium-ion batteries

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