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Hydrogel-supported poly(L-lactic acid) and polystyrene microsphere-based three-dimensional culture systems for in vitro cell expansion

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Frontiers of Materials Science 2024年第2期18卷 129-137页

作者： Huaying Hao Lihong Sun Jiaxuan chen Jun liang State Key Laboratory of Food Nutrition and Safety Tianjin University of Science&TechnologyTianjin 300457China College of Light Industry Science and Engineering Tianjin University of Science&TechnologyTianjin 300457China College of Food Science and Engineering Tianjin University of Science&TechnologyTianjin 300457China

The in vitro expansion of stem cells is important for their application in different life science fields such as cellular tissue and organ *** objective of this paper was to achieve static cell culture in vitro through peptide hydrogel-supported microspheres(MSs).The peptides,with their gel-forming properties,microstructures,and mechanical strengths characterized,were found to have good support for the MSs and to be *** internal structures of poly(L-lactic acid)microspheres(PLLA-MSs)and polystyrene microspheres(PS-MSs)made in thelaboratory were observed and statistically analyzed in terms of particle size and pore size,following which the co-cultured MSs with cells were found to have good cell *** addition,three-dimensional(3D)culturing of cells was performed on the peptide and microcarrier composite scaffolds to measure cell viability and cell *** results showed that the peptides could be stimulated by the culture medium to self-assembly form a 3D fiber network *** the peptide-Ms composite scaffold-based cell culture system,further enhancement of the cell culture effect was *** peptide-Ms composite scaffolds have great potential for the application in 3D cell culture and in vitro cellexpansion.

关键词： microcarrier microsphere peptide hydrogel cell scaffold three-dimensional culture cell expansion

Uphill or downhill?Cropland use change and its drivers from the perspective of slope spectrum

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Journal of Mountain Science 2024年第2期21卷 484-499页

作者： PAN Sipei liang Jiale chen Wanxu PENG Yelin College of Land Management Nanjing Agricultural UniversityNanjing 210095China National&Local Joint Engineering Research Center for Rural Land Resources Use and Consolidation Nanjing 210095China Jiangsu Provincial Key Laboratory of Geographic Information Technology School of Geography and Ocean ScienceNanjing UniversityNanjing 210023China Key Laboratory of Natural Resources Monitoring and Supervision in Southern Hilly Region Ministry of Natural ResourcesChangsha 410118China Yunnan Key Laboratory of Plateau Geographic Processes and Environmental Changes Faculty of GeographyYunnan Normal UniversityKunming 650500China Hubei Key Laboratory of Regional Ecology and Environmental Change School of Geography and Information EngineeringChina University of GeosciencesWuhan 430074China

The continuous decrease of low-slope cropland resources caused by construction land crowding poses huge threat to regional sustainable development and food *** spectrum analysis of topographic and geomorphic features is considered as a digital terrain analysis method which reflects the macro-topographic features by using micro-topographic ***,pieces of studies have extended the concept of slope spectrum in the field of geoscience to construction land to explore its expansion law,while research on the slope trend of cropland from that perspective remains *** address the gap,in virtue of spatial analysis and geographically weighted regression(GWR)model,the cropland use change in the Yangtze River Basin(YRB)from 2000 to 2020 was analyzed and the driving factors were explored from the perspective of slope *** showed that the slope spectrum curves of cropland area-frequency in the YRB showed a first upward then a downward *** change curve of the slope spectrum of cropland in each province(municipality)exhibited various distribution *** analysis of morphological parameters of cropland slope spectrum revealed that the further down the YRB,the stronger the flattening characteristics,the more obvious the *** province experienced the greatest downhill cropland climbing(CLC)was Shannxi,while province experienced the highest uphill CLC was *** most common cropland use change type in the YRB was horizontal expansion *** factors affecting average cropland climbing index(ACCI)were quite stable in different periods,while population density(POP)changed from negative to positive during the study *** research is of practical significance for the rational utilization of cropland at the watershed scale.

关键词： Cropland climbing Land use change Slope spectrum Driving factors Geographically weighted regression Yangtze River Basin

NiO-Doped Fe_(2)O_(3)/MgO Properties for the Chemical Looping Oxidative Dehydrogenation of Ethane

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China Petroleum Processing & Petrochemical Technology 2024年第1期26卷 27-33页

作者： liang Hao chen Junjie Sun Jie Sun Hui Shenyang Ligong University Shenyang 110159China Fushun Ecology Environment Bureau Qingyuan County Branch Fushun 113399China

Ethane chemical looping oxidative dehydrogenation(CL-ODH)to ethylene is a new technology for ethylene ***_(2)O_(3)/MgO oxygen carrier was prepared using the co-precipitation *** influence of added NiO and its different loadings on Fe_(2)O_(3)/MgO were ***,a series of oxygen carriers were applied in the CL-ODH of the ethane cycle ***-Emmett-Teller(BET),X-ray diffractometry(XRD),X-ray photoelection spectroscopy(XPS),and H2-temperature programmed reduction(TPR)were used to characterize the physicochemical properties of these oxygen *** was confirmed that an interaction between NiO and Fe_(2)O_(3) occurred based on the XPS and H2-TPR *** on the CL-ODH activity performance tests conducted in a fixed-bed reactor,it was revealed that ethylene selectivity was significantly improved after NiO ***_(2)O_(3)-10%NiO/MgO showed the best activity performance with 93%ethane conversion and 50%ethylene selectivity at a reaction temperature of 650℃,atmospheric pressure,and space velocity of 7500 mL/(g·h).

关键词： chemical looping oxidative dehydrogenation oxygen carrier Fe_(2)O_(3)/MgO NiO

Fine-grained grid computing model for Wi-Fi indoor localization in complex environments

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Journal of Electronic Science and Technology 2024年第1期22卷 42-52页

作者： Yan liang Song chen Xin Dong Tu Liu School of Computer Engineering Chengdu Technological UniversityChengdu611730China HAN Networks Corporation Limited Beijing100094China

The fingerprinting-based approach using the wireless local area network(WLAN)is widely used for indoor ***,the construction of the fingerprint database is quite *** when the position of the access point(AP)or wall changes,updating the fingerprint database in real-time is *** appropriate indoor localization approach,which has a low implementation cost,excellent real-time performance,and high localization accuracy and fully considers complex indoor environment factors,is preferred in location-based services(LBSs)*** this paper,we proposed a fine-grained grid computing(FGGC)model to achieve decimeter-level localization *** points(RPs)are generated in the grid by the FGGC ***,the received signal strength(RSS)values at each RP are calculated with the attenuation factors,such as the frequency band,three-dimensional propagation distance,and walls in complex *** a result,the fingerprint database can be established automatically without manual measurement,and the efficiency and cost that the FGGC model takes for the fingerprint database are superior to previous *** proposed indoor localization approach,which estimates the position step by step from the approximate grid location to the fine-grained location,can achieve higher real-time performance and localization accuracy *** mean error of the proposed model is 0.36 m,far lower than that of previous ***,the proposed model is feasible to improve the efficiency and accuracy of Wi-Fi indoor *** also shows high-accuracy performance with a fast running speed even under a large-size *** results indicate that the proposed method can also be suitable for precise marketing,indoor navigation,and emergency rescue.

关键词： Fine-grained grid computing (FGGC) Indoor localization Path loss Random forest Reference points(RPs)

Multidimensional regulation of Ti-Zr-Cr-Mn hydrogen storage alloys via Y partial substitution

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Nano Research 2024年第5期17卷 4211-4220页

作者： Haixiang Xiu Wanqiang Liu Dongming Yin Nan Ding Wenfeng Qiao Shaolei Zhao long liang Cong Liu Shaohua Wang Qingshuang Wang Bingbing chen Limin Wang Yong cheng School of Materials Science and Engineering Changchun University of Science and TechnologyChangchun 130022China State Key Laboratory of Rare Earth Resources Utilization Changchun Institute of Applied ChemistryChinese Academy of Sciences(CAS)Changchun 130022China School of Applied Chemistry and Engineering University of Science and Technology of ChinaHefei 230026China Department of Energy Science and Engineering Nanjing Tech UniversityNanjing 211816China National Engineering Research Center of Nonferrous Metals Materials and Products for New Energy GRINM Group Co.Ltd.Beijing 100088China GRIMAT Engineering Institute Co. Ltd.Beijing 101407China College of Life Science and Technology Changchun University of Science and TechnologyChangchun 130022China

High density and safe storage of hydrogen are the preconditions for the large-scale application of hydrogen ***,the hydrogen storage properties of Ti_(0.6)Zr_(0.4)Cr_(0.6)Mn_(1.4) alloys are systematically studied by introducing Y element instead of Ti element through vacuum arc *** the partial substitution of Y,a second phase of rare earth oxide is added in addition to the main suction hydrogen phase,C14 Laves *** to the unique properties of rare earth elements,the partial substitution of Y can not only improve the activation properties and plateau pressure of the alloys,but also increase the effective hydrogen storage capacity of the *** comprehensive properties of hydrogen storage alloys are improved by multidimensional regulation of rare earth *** them,Ti_(0.552)Y_(0.048)Zr_(0.4)Cr_(0.6)Mn_(1.4) has the best comprehensive *** alloy can absorb hydrogen without activation at room temperature and 5 MPa,with a maximum hydrogen storage capacity of 1.98 wt.%.At the same time,it reduces the stability of the hydride and the enthalpy change value,making it easier to release *** theoretical analysis and first-principle simulation,the results show that the substitution of Y element reduces the migration energy barrier of hydrogen and the structural stability of the system,which is conducive to hydrogen *** alloy has superior durability compared to the original alloy,and the capacity retention rate was 96.79%after 100 hydrogen absorption/desorption cycles.

关键词： AB_(2)-type hydrogen storage alloy rare earth element first-principles simulation multidimensional regulation

A visual modeling method for spatiotemporal and multidimensional features in epidemiological analysis:Applied COVID-19 aggregated datasets

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Computational Visual Media 2024年第1期10卷 161-186页

作者： Yu Dong Christy Jie liang Yi chen Jie Hua School of Computer Science University of Technology SydneySydneyNSW2007Australia Beijing Key Laboratory of Big Data Technology for Food Safety Beijing Technology and Business UniversityBeijing100048China

The visual modeling method enables flexible interactions with rich graphical depictions of data and supports the exploration of the complexities of epidemiological ***,most epidemiology visualizations do not support the combined analysis of objective factors that might influence the transmission situation,resulting in a lack of quantitative and qualitative *** address this issue,we developed a portrait-based visual modeling method called+*** method considers the spatiotemporal features of virus transmission patterns and multidimensional features of objective risk factors in communities,enabling portrait-based exploration and comparison in epidemiological *** applied+msRNAer to aggregate COVID-19-related datasets in New South Wales,Australia,combining COVID-19 case number trends,geo-information,intervention events,and expert-supervised risk factors extracted from local government area-based *** perfected the+msRNAer workflow with collaborative views and evaluated its feasibility,effectiveness,and usefulness through one user study and three subject-driven case *** feedback from experts indicates that+msRNAer provides a general understanding for analyzing comprehension that not only compares relationships between cases in time-varying and risk factors through portraits but also supports navigation in fundamental geographical,timeline,and other factor *** adopting interactions,experts discovered functional and practical implications for potential patterns of long-standing community factors regarding the vulnerability faced by the *** confirmed that+msRNAer is expected to deliver visual modeling benefits with spatiotemporal and multidimensional features in other epidemiological analysis scenarios.

关键词： visual modeling epidemiological analysis spatiotemporal multidimensional COVID-19

China’s Proactive Fiscal Policy

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China Economist 2024年第1期19卷 58-74页

作者： Xing Li chen long Chinese Academy of Fiscal Sciences BeijingChina

In contrast to the traditional Western approach to macro-fiscal management,China’s proactive fiscal policy is founded on a people-centered development philosophy and,with distinctive Chinese characteristics,is a significant policy innovation of macroeconomic management in the Chinese *** there are notable distinctions between the Western“Keynesian”and the“nonKeynesian”schools of thought,both of these approaches’core policy goals and methodological roots are the same,composing the traditional Western macro-fiscal *** approach faces increasing real ***’s proactive fiscal policy,however,places greater emphasis on future potential growth rates in addition to equilibrium between supply and demand,achieving a fiscal policy transformation with a new *** this paper we argue that with such a new approach,China should reconsider the nature and reasonable level of the fiscal deficit,the function and risk assessment criteria of government debt,the scope and effects of reductions in taxes and fees,its approach and focus of demand management,and the costs and resulting efficiencies of policies in order to develop a new fiscal policy paradigm that is more in line with its stated goals.

关键词： Proactive fiscal policy fiscal approach potential growth rate

Exploration for the Priority of HIV Intervention:Modelling Health Impact and Cost-Effectiveness—Six Cities,Eastern China,2019-2028

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China CDC weekly 2024年第20期6卷 463-468,I0008-I0014页

作者： Youran Zhang Lili Wang Zhen Jiang Hongjing Yan Xiaoxia Liu Jing Gu Guoyong Wang Xiaosong cheng Qiyan Leng Qisui long Zimian liang Jing Wang liang liang Yanchao Qiu Lin chen Hang Hong School of Health Service Management Anhui Medical UniversityHefei CityAnhui ProvinceChina Division of Prevention and intervention National Center for AIDS and STD Control and PreventionChinese Center for Disease Control and PreventionBeijingChina Jiangsu Provincial Center for Disease Control and Prevention Nanjing CityJiangsu ProvinceChina Zhenjiang Center for Disease Control and Prevention Zhenjiang CityJiangsu ProvinceChina Wuxi Center for Disease Control and Prevention Wuxi CityJiangsu ProvinceChina Shandong Provincial Center for Disease Control and Prevention Jinan CityShandong ProvinceChina Yantai Center for Disease Control and Prevention Yantai CityShandong ProvinceChina Guangdong Provincial Center for Disease Control and Prevention Guangzhou CityGuangdong ProvinceChina Foshan Center for Disease Control and Prevention Foshan CityGuangdong ProvinceChina Hebei Provincial Center for Disease Control and Prevention Shijiazhuang CityHebei ProvinceChina Shijiazhuang Center for Disease Control and Prevention Shijiazhuang CityChina Zhejiang Provincial Center for Disease Control and Prevention Hangzhou CityZhejiang ProvinceChina Ningbo Center for Disease Control and Prevention Ningbo CityZhejiang ProvinceChina

Introduction:In order to enhance the effectiveness of resource allocation,regions must tailor their responses to their specific epidemiological and economic ***:Utilizing Spectrum software,we projected the cost-effectiveness of 10 chosen HIV interventions in six cities in eastern China from 2019 to *** assessed three scenarios—Base,Achievable,and Idealized—for each *** analysis included the projected number of HIV infections and deaths averted,as well as the incremental costeffectiveness ratios for each intervention in the six ***:In Shijiazhuang,Wuxi,Yantai,and Zhenjiang,cities with initially low antiretroviral therapy(ART)coverage,ART showed significant effectiveness,especially for ***,in Foshan and Ningbo,where ART coverage was notably high,oral pre-exposure prophylaxis(PrEP)for men who have sex with men(MSM)proved effective in the Idealized *** outreach,ART for males,and ART for females demonstrated cost-effectiveness across all six cities in both Achievable and Idealized scenarios at the predefined thresholds for each ***:Maintaining an appropriate coverage rate for outreach to MSM can lead to *** cities with low ART coverage,scaling up ART remains a crucial *** regions with high ART coverage,consideration may be given to the utilization of oral PrEP for MSM individuals,requiring budget allocation.

关键词： Eastern Ningbo Impact

Particle residence time distribution and axial dispersion coefficient in a pressurized circulating fluidized bed by using multiphase particle-in-cell simulation

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Chinese Journal of Chemical Engineering 2024年第5期69卷 167-176页

作者： Jinnan Guo Daoyin Liu Jiliang Ma Cai liang Xiaoping chen Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education Southeast UniversityNanjing 210096China

The particle residence time distribution(RTD)and axial dispersion coefficient are key parameters for the design and operation of a pressurized circulating fluidized bed(PCFB).In this study,the effects of pressure(0.1-0.6 MPa),fluidizing gas velocity(2-7 m·s^(-1)),and solid circulation rate(10-90 kg·m^(-2)·s^(-1))on particle RTD and axial dispersion coefficient in a PCFB are numerically investigated based on the multiphase particle-in-cell(MP-PIC)*** details of the gas-solid flow behaviors of PCFB are *** on the gas-solid flow pattern,the particles tend to move more orderly under elevated *** an increase in either fluidizing gas velocity or solid circulation rate,the mean residence time of particles decreases while the axial dispersion coefficient *** an increase in pressure,the core-annulus flow is strengthened,which leads to a wider shape of the particle RTD curve and a larger mean particle residence *** back-mixing of particles increases with increasing pressure,resulting in an increase in the axial dispersion coefficient.

关键词： Pressurized circulating fluidized bed MP-PIC method Residence time distribution Axial dispersion coefficient