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Ultrafine Ru nanoparticles anchored on core-shell structured zeolite-carbon for efficient catalysis of hydrogen generation

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Rare Metals 2023年第7期42卷 2324-2334页

作者： Yue-Wei Wei Guang Yang xi-xi xu Yan-Yan Liu Nai-xin Kang Bao-Jun Li Yong-Zhao Wang Yong-xiang Zhao School of Chemistry and Chemical Engineering Shanxi UniversityTaiyuan030006China Engineering Research Center of Ministry of Education for Fine Chemicals Shanxi UniversityTaiyuan030006China Tobacco College of Henan Agricultural University Zhengzhou450002China College of Science Henan Agricultural UniversityZhengzhou450002China ISM UMR CNRS Nº5255Univ.BordeauxTalence Cedex33405France Research Center of Green Catalysis College of ChemistryZhengzhou UniversityZhengzhou450001China

As a promising route to hydrogen production,hydrolysis of ammonia borane(AB)aqueous solution requires efficient and stable *** this paper,a carbon-coated zeolite is prepared by high temperature calcination using glucose as carbon *** Ru nanoparticles are anchored on the composite support with core-shell structure using a simple in situ reduction *** prepared catalyst expressed outstanding catalytic activity in the hydrolytic dehydrogenation of *** effects of support prepared by different synthesis parameters on the performance of catalyst are *** Ru/S-1@C(RSC-2)catalyst exhibited the highest catalytic activity for hydrolytic dehydrogenation of AB with a turnover frequency of 892 min^(-1)at room *** performance is superior to that of many catalysts previously *** excellent catalytic activity is attributed to the carbon layer on catalyst surface effectively limiting the aggregation of Ru nanoparticles in the hydrolysis *** zeolite also plays a role in preactivation of *** pre-activation accelerates the ratelimiting step of water dissociation in the *** kinetic studies for determining the activation energy(E_(a)=36.8 kJ·mol^(-1))were based on reaction *** effects of catalyst concentration,AB concentration and NaOH concentration on hydrolysis rate of AB were further *** high-performance catalysts and the preparation method in this study have wide application prospects in the field of clean energy.

关键词： Ammonia borane Ruthenium Hydrogen generation Carbon Zeolite

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Prescribed Performance Tracking Control of Time-Delay Nonlinear Systems With Output Constraints

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IEEE/CAA Journal of Automatica Sinica 2024年第7期11卷 1557-1565页

作者： Jin-xi Zhang Kai-Di xu Qing-Guo Wang IEEE the State Key Laboratory of Synthetical Automation for Process Industries Northeastern UniversityShenyang 110819China Institute of Artificial Intelligence and Future Networks Beijing Normal UniversityZhuhai 519087 Guangdong Key Laboratory of Artificial Intelligence and Multi-Modal Data Processing Beijing Normal University-Hong Kong Baptist University United International CollegeZhuhai 519087

The problem of prescribed performance tracking control for unknown time-delay nonlinear systems subject to output constraints is dealt with in this paper. In contrast with related works, only the most fundamental requirements, i.e., boundedness and the local Lipschitz condition, are assumed for the allowable time delays. Moreover, we focus on the case where the reference is unknown beforehand, which renders the standard prescribed performance control designs under output constraints infeasible. To conquer these challenges, a novel robust prescribed performance control approach is put forward in this ***, a reverse tuning function is skillfully constructed and automatically generates a performance envelop for the tracking error. In addition, a unified performance analysis framework based on proof by contradiction and the barrier function is established to reveal the inherent robustness of the control system against the time delays. It turns out that the system output tracks the reference with a preassigned settling time and good accuracy,without constraint violations. A comparative simulation on a two-stage chemical reactor is carried out to illustrate the above theoretical findings.

关键词： Nonlinear systems output constraints prescribed performance reference tracking time delays

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Improving lipid production by Rhodotorula glutinis for renewable fuel production based on machine learning

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Frontiers of Chemical Science and Engineering 2024年第5期18卷 23-35页

作者： Lihe Zhang Changwei Zhang xi Zhao Changliu He xu Zhang National Energy R&D Center for Biorefinery Beijing University of Chemical TechnologyBeijing 100029China Collage of Life Science and Technology Beijing University of Chemical TechnologyBeijing 100029China Beijing Key Laboratory of Bioprocess Beijing University of Chemical TechnologyBeijing 10029China

Microbial lipid fermentation encompasses intricate complex cell growth processes and heavily relies on expert experience for optimal *** modeling of the fermentation process assists researchers in making intelligent decisions,employing logical reasoning and strategic planning to optimize lipid *** this study,the effects of medium components and concen-trations on lipid fermentation were investigated,*** then,leveraging the collated data,a variety of machine learning algorithms were used to model and optimize the lipid fermentation *** models,based on artificial neural networks and support vector machines,achieved R?values all higher than 0.93,ensuring accurate predictions of the fermentation *** linear regression was used to evaluate the respective target parameter,which were affected by the medium components of lipid ***,single and multi-objective optimiza-tion were conducted for lipid fermentation using the genetic *** results demonstrated the maximum biomass of 50.3 g·L^(-1) and maximum lipid concentration of 14.1 g:L^(-1) with the error between the experimental and predicted values less than 5%.The results of the multi-objective optimization reveal the synergistic and competitive relationship between biomass,lipid concentration,and conversion rate,which lay a basis for in-depth optimization and amplification.

关键词： microbial lipid machine learning artificial neural network support vector machine genetic algorithm

Colloid-facilitated release of polybrominated diphenyl ethers at an e-waste recycling site: evidence from undisturbed soil core leaching experiments

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Frontiers of Environmental Science & Engineering 2024年第2期18卷 91-101页

作者： Zebin Huo Mengjun xi Lianrui xu Chuanjia Jiang Wei Chen College of Environmental Science and Engineering Ministry of Education Key Laboratory of Pollution Processes and Environmental CriteriaTianjin Key Laboratory of Environmental Remediation and Pollution ControlNankai UniversityTianjin 300350China

Polybrominated diphenyl ethers (PBDEs), a class of persistent organic pollutants, have been frequently detected in soil at e-waste recycling sites. However, the key factors controlling the transport of PBDEs from surface soil to the vadose zone and groundwater are unclear. Here, colloid-enhanced leaching of PBDEs from undisturbed soil cores collected at an e-waste recycling site in Tianjin, China, is reported. Spatially heterogeneous release of colloids and PBDEs was observed in all the tested soil cores under chemical and hydrodynamic perturbations, indicating the presence of preferential flow paths. Colloid concentration in the effluent significantly increased as ionic strength decreased (from 10 to 0.01 mmol/L), probably due to the stronger electrostatic repulsion between colloidal particles and the soil matrix at lower ionic strength. In contrast, colloid mobilization was not significantly affected by the changes in pH of the influent (from 4.0 to 10.0) and flow rate (from a Darcy velocity of 1.5 to 6.0 cm/h). The concentrations of 2,2′,3,3′,4,4′,5,5′,6,6′-decabromodiphenyl ether (BDE-209), the predominant PBDE congener at the site, detected in the leachate (ranging from 1.09 to 3.43 ng/L) were much lower than previously reported results from packed column leaching tests, and were positively correlated with colloid concentrations. This indicates that remobilization of colloids at e-waste recycling sites can promote the leaching and downward migration of PBDEs from surface soil. The findings highlight the potential risk of surface soil PBDE contamination to groundwater quality and call for further understanding of colloid-facilitated transport for predicting the fate of PBDEs at e-waste recycling sites.

关键词： Polybrominated diphenyl ether Colloid-facilitated transport E-waste recycling site Undisturbed soil core Groundwater quality

Liquid metal biomaterials: translational medicines,challenges and perspectives

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National Science Review 2024年第2期11卷 264-284页

作者： Hanchi xu Jincheng Lu Yikuang xi xuelin Wang Jing Liu Department of Biomedical Engineering School of Medicine Tsinghua University Beijing Tsinghua Changgung Hospital School of Clinical Medicine Tsinghua University Shanghai World Foreign Language Academy Beijing Advanced Innovation Center for Biomedical Engineering School of Engineering MedicineBeihang University Beijing Key Lab of Cryo-Biomedical Engineering and Key Lab of Cryogenics Technical Institute of Physics and Chemistry Chinese Academy of Sciences

Until now, significant healthcare challenges and growing urgent clinical requirements remain incompletely addressed by presently available biomedical materials. This is due to their inadequate mechanical compatibility, suboptimal physical and chemical properties, susceptibility to immune rejection, and concerns about long-term biological safety. As an alternative, liquid metal(LM) opens up a promising class of biomaterials with unique advantages like biocompatibility, flexibility, excellent electrical conductivity,and ease of functionalization. However, despite the unique advantages and successful explorations of LM in biomedical fields, widespread clinical translations and applications of LM-based medical products remain limited. This article summarizes the current status and future prospects of LM biomaterials, interprets their applications in healthcare, medical imaging, bone repair, nerve interface, and tumor therapy, *** to translate LM materials into medicine and obstacles encountered in practices are *** that, we outline a blueprint for LM clinics, emphasizing their potential in making new-generation artificial organs. Last, the core challenges of LM biomaterials in clinical translation, including bio-safety,material stability, and ethical concerns are also discussed. Overall, the current progress, translational medicine bottlenecks, and perspectives of LM biomaterials signify their immense potential to drive future medical breakthroughs and thus open up novel avenues for upcoming clinical practices.

关键词： liquid metal biomaterials translational medicine clinical device healthcare therapeutics

Exact satisfiability and phase transition analysis of the regular(k,d)-CNF formula

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Frontiers of Computer Science 2024年第1期18卷 263-265页

作者： Guoxia NIE Daoyun xu xi WANG Zaijun ZHANG College of Computer Science and Technology Guizhou UniversityGuiyang 550025China School of Mathematics and Statistics Qiannan Normal University for NationalitiesDuyun 558000China Key Laboratory of Industrial Automation and Machine Vision of Qiannan Duyun 558000China

1Introduction The satisfiability(SAT)problem has been considered the"seed"of other NP-complete *** regular partial exact(k,d)-SAT problem is an important extension of the SAT *** any(k,d)-CNF formula with a variable set V,V'is a proper subset of V,the problem involves determining whether a truth assignment set on V'exists such that only a literal in each clause is *** V'=V,it is a regular exact(k,d)-SAT ***,both experimental verifications and theoretical analyses of k-SAT problem have shown that the ratioα(clause constraint density)of the number of clauses m to the number of variables n is an important parameter affecting the satisfiability of the formula[1].However,the regular(k,d)-SAT problem has the same clause constraint density d/k.

关键词： formula constraint exact

Development and parentage analysis of SNP markers for Chestnut-vented Nuthatch(Sitta nagaensis)based on ddRAD-seq data

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Avian Research 2024年第2期15卷 271-278页

作者： Qingmiao Yuan xi Lu Ruixin Mo xianyin xu xu Luo Yubao Duan Key Laboratory for Conserving Wildlife with Small Populations in Yunnan Southwest Forestry UniversityKunming 650224China Key Laboratory for Forest Resources Conservation and Utilization in the Southwest Mountains of China Ministry of EducationSouthwest Forestry UniversityKunming 650224China Key Laboratory of Forest Disaster Warning and Control of Yunnan Province Southwest Forestry UniversityKunming 650224China College of Forestry Southwest Forestry UniversityKunming 650224China Administration of Zixi Mountain Provincial Nature Reserve Chuxiong 675008China

Extra-pair paternity(EPP)is commonly found in socially monogamous birds,especially in small passerine birds,and there are interspecific and intraspecific variations in the extent of *** Chestnut-vented Nuthatch(Sitta nagaensis)is a socially monogamous passerine bird,and verifying whether this species has EPP relies on parentage *** is not known to have *** this study,we developed SNP markers of this species that are informative for parentage analysis from double digest restriction site-associated DNA sequencing(ddRAD-seq)data.A panel consisting of 50 SNP markers,with a mean heterozygosity of 0.343,was used to resolve 95% of nestlings to *** combined exclusion probabilities for the first parent and second parent were 0.991 and 0.9999,*** panel of SNP markers is a powerful tool for parentage assignments in *** addition,we found that three offspring(7.9%)from three nests(23.1%)were the result of extra-pair fertilization out of 38 offspring in 13 *** study provided information on parentage analysis that has not been reported before in *** also supplemented the understudied EPP behavior of birds in Asia,contributing to a general understanding of the EPP behaviors of birds.

关键词： Chestnut-vented Nuthatch ddRAD sequencing Extra-pair paternity Parentage analysis SNPs

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Enhancing competency of clinical research nurses:A comprehensive training and evaluation framework

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World Journal of Clinical Cases 2024年第7期12卷 1378-1381页

作者： Yang-xi Liu Yi xu Tumor Interventional Department Taizhou Municipal HospitalTaizhou 318099Zhejiang ProvinceChina

The Sun et al's training program for clinical research nurses(CRNs)in the World Journal of Clinical Cases is a comprehensive and scientific *** includes structured frameworks for CRN training,aiming to improve CRN *** program emphasizes practical abilities,updates training content,and improves evaluation *** cultivation of CRN talents focuses on enhancing the training system,establishing a multifaceted evaluation framework,and continuously refining the training *** feedback and evalua-tion are essential to improve CRNs'competency in practical settings.

关键词： Clinical research nurse Framework Nurse Operations Practice Structure

Metal±organic cage as fluorescent probe for LiPF6 in lithium batteries

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Green Energy & Environment 2024年第10期9卷 1592-1600页

作者： xi Li Dehua xu Aoxuan Wang Chengxin Peng xingjiang Liu Jiayan Luo Key Laboratory for Green Chemical Technology of Ministry of Education School of Chemical Engineering and TechnologyTianjin University School of Materials Science and Engineering University of Shanghai Science and Technology State Key Laboratory of Metal Matrix Composites School of Materials Science and EngineeringShanghai Jiao Tong University

Lithium hexafluorophosphate （LiPF6）,the most commonly used lithium battery electrolyte salt,is vulnerable to heat and *** and qualitative determination the variation of Li PF6have always relied on advanced ***,we develop a fast,convenient,high-selective fluorescence detection method based on metal±organic cages （MOC）,whose emission is enhanced by nearly 20 times in the presence of Li PF6with good stability and photobleaching *** fluorescent probe can also detect moisture in battery *** propose and verify that the luminescence enhancement is due to the presence of hydrogen bond-induced enhanced emission effect in *** excitation-emission matrix spectra and variable-temperature nuclear magnetic resonance spectroscopy are employed to clarify the role of hydrogen bonds in guest-loaded *** functional theory （DFT） calculation is applied to simulate the structure of host-guest complexes and estimate the adsorption energy involved in the *** precisely matched lock-and-key model paves a new way for designing and fabricating novel host structures,enabling specific recognition of other target compounds.

关键词： Metal-organic cage Selective fluorescence probe Moisture detection Hydrogen bond Host-guest complex