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Numerical Study of Flow and Heat Transfer Characteristics of Shell-and-Tube Molten Salt Electric Heater with Circularly Perforated Baffles

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Journal of Thermal Science 2025年第1期34卷 24-33页

作者： LIN Yongjie ZHANG Cancan WU Yuting ZHANG Yi LU Yuanwei key laboratory of Heat Transfer and Energy Conversion National User-Side Energy Storage Innovation Research and Development CenterBeijing University of TechnologyBeijing 100124China

Numerical simulations of the flow and heat transfer characteristics of four shell-and-tube molten salt electric heaters with different perforation rates was ***-and-tube electric heaters have the same geometry and tube arrangement,and all of them use single segmental baffles,but there exist four different baffle openings(φ),i.e.,0%,2.52%,4.06%,and 6.31%.The results indicated that the reasonable baffle opening could significantly reduce the shell-side pressure drop,effectively decreasing the shell-side flow dead zone *** can eliminate the local high-temperature phenomenon on the surface of electric heating tubes,but the heat transfer coefficient is slightly *** perforated schemes significantly reduce shell-side pressure drop compared to the baseline solution without open *** particular,the φ=6.31% scheme exhibits the optimal performance among all the schemes,with a maximum reduction of up to 50.50% in shell-side pressure drop relative to the unopened holes *** heat transfer coefficient is the highest for φ=0%,exhibiting a range of5.26% to 5.73%,5.14% to 5.99%,and 7.31% to 8.54% higher than φ=2.52%,4.06%,and 6.31%,respectively,within the calculated *** composite index h/(Δp)^(1/3)was higher for all open-hole solutions than that for the unopened-hole *** best overall performance was for φ=6.31%,which improved the composite index by15.29%to 17.18%over the unopened-hole solution.

关键词： molten salt electric heater perforated baffles heat transfer

MoS2 synaptic transistor with one-step manufacture

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Science China(Information Sciences) 2025年第1期68卷 357-365页

作者： Yihao GUO Yang WANG Wenjie DENG Yi WU Jingtao LI Kexin LI Yuehui ZHAO Songlin YU Xiaoting WANG Yongzhe ZHANG Hui YAN key laboratory of optoelectronics Technology of Education Ministry of China Faculty of Information TechnologyBeijing University of Technology key laboratory of Advanced Functional Materials Ministry of Education Faculty of Materials and ManufacturingBeijing University of Technology The 11th Research Institute of Electronics Technology Group Corporation

The synaptic transistor,which is a neuromorphic device with brain-like functions,has garnered significant attention due to characteristics such as low energy consumption,high integration,multiple functions,and high computational ***,the current synaptic transistor possesses a complicated structure and involves complex manufacturing steps,which is not conducive to low-cost,large-scale bionic ***,we introduce a simple MoS2synaptic transistor exhibiting robust synaptic *** transistor utilizes magnetron sputtering manufacture to combine the process of device metal electrode deposition and the introduction of defect states,which helps streamline the manufacturing process into a single *** long-term potentiation and long-term depression in photoelectric coordination are initially ***,biological functions,such as double pulse facilitation and the transformation behavior of short-term memory to long-term memory,are thoroughly evaluated,along with learning-forgetting-relearning ***,the device exhibits robust synaptic plasticity until incident light angles down to 30° to imitate the multi-to-one axon-cellular ***,a classical simulation of Pavlov's dog conditioned reflex is demonstrated along with the multiview extraction *** experimental results demonstrate a promising synaptic transistor with a simple structure,manufacturing technique,and excellent *** further indicates the potential for large-scale integration of bionic neuromorphic systems.

关键词： process optimization artificial synaptic device one-stepmanufacture synaptic plasticity bionic simulation

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Metagenomics reveals the resistance patterns of electrochemically treated erythromycin fermentation residue

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Journal of Environmental Sciences 2025年第2期148卷 567-578页

作者： Jieya Zhou HaoWu Haiyan Wang ZongruWu Lihu Shi Shulei Tian Li-an Hou State key laboratory of Environmental Criteria and Risk Assessment Chinese Research Academy of Environmental SciencesBeijing 100012China State key laboratory of Water Environment Simulation School of EnvironmentBeijing Normal UniversityBeijing 100875China Inner Mongolia Autonomous Region Solid Waste and Soil Ecological Environment Technology Center Hohhot 010020China

Erythromycin fermentation residue(EFR)represents a typical hazardous waste produced by the microbial pharmaceutical *** electrolysis is promising for EFR disposal,its microbial threats remain ***,metagenomics was coupled with the random forest technique to decipher the antibiotic resistance patterns of electrochemically treated *** showed that 95.75%of erythromycin could be removed in 2 *** temporarily influenced EFRmicrobiota,where the relative abundances of Proteobacteria and Actinobacteria increased,while those of Fusobacteria,Firmicutes,and Bacteroidetes decreased.A total of 505 antibiotic resistance gene(ARG)subtypes encoding resistance to 21 antibiotic types and 150 mobile genetic elements(MGEs),mainly including plasmid(72)and transposase(52)were assembled in *** linear regression models were identified among microbial richness,ARG subtypes,and MGE numbers(r^(2)=0.50-0.81,p<0.001).Physicochemical factors of EFR(Total nitrogen,total organic carbon,protein,and humus)regulated ARG and MGE assembly(%IncMSE value=5.14-14.85).The core ARG,MGE,and microbe sets(93.08%-99.85%)successfully explained 89.71%-92.92%of total ARG and MGE ***,gene aph(3 )-I,transposase tnpA,and Mycolicibacterium were the primary drivers of the resistance dissemination *** study also proposes efficient resistance mitigation measures,and provides recommendations for future management of antibiotic fermentation residue.

关键词： Erythromycin fermentation residue (EFR) Microbial pharmaceutical industry Disposal strategy Metagenomics Antibiotic fermentation residue management

Inexact proximal gradient algorithm with random reshuffling for nonsmooth optimization

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Science China(Information Sciences) 2025年第1期68卷 219-237页

作者： Xia JIANG Yanyan FANG Xianlin ZENG Jian SUN Jie CHEN National key Lab of Autonomous Intelligent Unmanned systems School of AutomationBeijing Institute of Technology beijing Institute of Technology Chongqing Innovation Center School of Electronic and Information Engineering Tongji University

Proximal gradient algorithms are popularly implemented to achieve convex optimization with nonsmooth regularization. Obtaining the exact solution of the proximal operator for nonsmooth regularization is challenging because errors exist in the computation of the gradient; consequently, the design and application of inexact proximal gradient algorithms have attracted considerable attention from researchers. This paper proposes computationally efficient basic and inexact proximal gradient descent algorithms with random reshuffling. The proposed stochastic algorithms take randomly reshuffled data to perform successive gradient descents and implement only one proximal operator after all data pass through. We prove the convergence results of the proposed proximal gradient algorithms under the sampling-without-replacement reshuffling *** computational errors exist in gradients and proximal operations, the proposed inexact proximal gradient algorithms can converge to an optimal solution neighborhood. Finally, we apply the proposed algorithms to compressed sensing and compare their efficiency with some popular algorithms.

关键词： proximal operator random reshuffling inexact computation compressed sensing nonsmooth optimization

CO_(2)-mediated bicarbonate conversion to concentrated formate in a CEM-based electrolyzer

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Journal of Energy Chemistry 2025年第1期100卷 605-611页

作者： Haocheng Xiong Donghuan Wu Haonan Li Andrew Li Qikun Hu Siyao Song Bingjun Xu Qi Lu State key laboratory of Chemical Engineering Department of Chemical EngineeringTsinghua UniversityBeijing 100084China College of Chemistry and Molecular Engineering Peking UniversityBeijing 100871China Ordos laboratory Inner Mongolia 017000China

Renewable energy-driven bicarbonate conversion to valuable chemicals presents an attractive strategy for mitigating CO_(2)emissions,as bicarbonate can be efficiently generated from the capture of atmospheric CO_(2)using alkaline solutions with reactive *** this work,we present a CO_(2)-mediated bicarbonate conversion to pure formate using a cation exchange membrane-based electrolyzer with a 25 cm^(2)electrode *** electrolysis achieved selectivities exceeding 75%for formate at a total current of 2.5 A,achieving formate concentrations up to 1.2 M and yields as high as 95%over extended *** techno-economic assessment confirmed the economic viability of the process,highlighting the potential for bicarbonate electrolysis as a sustainable method for producing valuable chemicals.

关键词： Electrocatalysis Techno-economic assessments Electrochemistry Flow electrolyzer

Barrierless reactions of C2 Criegee intermediates with H_(2)SO_(4)and their implication to oligomers and new particle formation

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Journal of Environmental Sciences 2025年第3期149卷 574-584页

作者： Yang Cheng Chao Ding Tianlei Zhang Rui Wang Ruxue Mu Zeyao Li Rongrong Li Juan Shi Chongqin Zhu Institute of Theoretical and Computational Chemistry Shaanxi Key Laboratory of CatalysisSchool of Chemical&Environment ScienceShaanxi University of TechnologyHanzhongShaanxi 723001China College of Chemistry Key Laboratory of Theoretical&Computational Photochemistry of Ministry of EducationBeijing Normal UniversityBeijing 100190China

The formation of oligomeric hydrogen peroxide triggered by Criegee intermediate maybe contributes significantly to the formation and growth of secondary organic aerosol(SOA).However,to date,the reactivity of C2 Criegee intermediates(CH_(3)CHOO)in areas contaminated with acidic gas remains poorly ***,high-level quantum chemical calculations and Born-Oppenheimer molecular dynamics(BOMD)simulations are used to explore the reaction of CH_(3)CHOO and H_(2)SO_(4)both in the gas phase and at the airwater *** the gas phase,the addition reaction of CH_(3)CHOO with H_(2)SO_(4)to generate CH_(3)HC(OOH)OSO_(3)H(HPES)is near-barrierless,regardless of the presence of water *** simulations showthat the reaction at the air-water interface is even faster than that in the gas *** calculations reveal that the HPES has a tendency to aggregate with sulfuric acids,ammonias,and water molecules to form stable clusters,meanwhile the oligomerization reaction of CH_(3)CHOO with HPES in the gas phase is both thermochemically and kinetically ***,it is noted that the interfacial HPES−ion can attract H_(2)SO_(4),NH_(3),(COOH)_(2)and HNO_(3)for particle formation from the gas phase to the water ***,the results of this work not only elucidate the high atmospheric reactivity of C2 Criegee intermediates in polluted regions,but also deepen our understanding of the formation process of atmospheric SOA induced by Criegee intermediates.

关键词： Criegee intermediates H_(2)SO_(4) Atmospheric behavior Air-water interface Chemical processes

Mechanism for Hydrothermal-carbothermal Synthesis of AlN Nanopowders

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无机材料学报 2025年第1期40卷 104-110,I0009-I0011页

作者： FENG Guanzheng YANG Jian ZHOU Du CHEN Qiming XU Wentao ZHOU Youfu key laboratory of optoelectronic Materials Chemistry and Physics Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002China Fujian Science&Technology Innovation laboratory for optoelectronic Information of China Fuzhou 350108China University of Chinese Academy of Sciences Beijing 100039China

Currently,the carbothermal reduction-nitridation(CRN)process is the predominant method for preparing aluminum nitride(AlN)*** AlN powder prepared by CRN process exhibits high purity and excellent sintering activity,it also presents challenges such as the necessity for high reaction temperatures and difficulties in achieving uniform mixing of its raw *** study presents a comprehensive investigation into preparation process of AlN nanopowders using a combination of hydrothermal synthesis and *** the hydrothermal reaction,a homogeneous composite precursor consisting of carbon and boehmite(γ-AlOOH)is synthesized at 200℃using aluminum nitrate as the aluminum source,sucrose as the carbon source,and urea as the *** the hydrothermal process,the precursor develops a core-shell structure,with boehmite tightly coated with carbon(γ-AlOOH@C)due to electrostatic *** with conventional precursor,the hydrothermal hybrid offers many advantages,such as ultrafine particles,uniform particle size distribution,good dispersion,high reactivity,and environmental *** carbon shell enhances thermodynamic stability of γ-Al_(2)O_(3) compared to the corundum phase(α-Al_(2)O_(3))by preventing the loss of the surface area in *** stability enables γ-Al_(2)O_(3) to maintain high reactivity during CRN process,which initiates at 1300℃,and concludes at 1400℃.The underlying mechanisms are substantiated through experiments and thermodynamic *** research provides a robust theoretical and experimental foundation for the hydrothermal combined carbothermal preparation of non-oxide ceramic nanopowders.

关键词： aluminum nitride carbothermal reduction-nitridation mechanism hydrothermal synthesis precursor

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Conjunctival microbiota variations in a subset of middleaged and elderly individuals from beijing,China

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International Journal of Ophthalmology(English edition) 2025年第2期18卷 237-243页

作者： Tian-Yao Zhao Yu-Chen Wang Ying-Juan Sun Jun-Yue Wang Xiao-Dan Jiang Xue-Min Li Ai-Hua Deng Department of Ophthalmology Peking University Third HospitalBeijing Key Laboratory of Restoration of Damaged Ocular NerveBeijing 100191China Fangshan Hospital beijing University of Chinese Medicine Beijing 102400China CAS key laboratory of Pathogenic Microbiology and Immunology Institute of MicrobiologyChinese Academy of SciencesBeijing 100101China State key laboratory of Animal Nutrition and Feeding Ministry of Agriculture and Rural Affairs Feed Industry CentreAgricultural UniversityBeijing 100193China

AIM:To isolate and identify the conjunctival microbiota of cataract patients and analyze the associated influencing ***:This study recruited 216 participants(216 eyes)from April 2022 to July *** the condition of no antibiotic use prior to cataract surgery,sterile swabs were used to collect samples from the lower conjunctival *** cultures were then conducted,followed by species identification through 16S rDNA gene *** factors associated with positive or negative bacterial isolation rates were analyzed,including age,gender,meibomian gland dysfunction(MGD),history of hypertension,history of diabetes,history of cancer,history of infectious diseases and the habit of wearing ***:Among the 216 eyes,78 eyes yielded isolates,with an isolation rate of 36.11%,detecting a total of 122 ***-positive rods accounted for 49.18%(60 strains),gram-positive cocci accounted for 45.08%(55 strains),gram-negative bacteria accounted for 4.92%(6 strains),and fungi accounted for 0.82%(1 strain).This study found that the most abundant genera in the conjunctival sac were Corynebacterium(42.62%),Staphylococcus(31.15%),Micrococcus(9.84%),Acinetobacter(4.10%),and Bacillus(3.28%).Furthermore,age(P=0.006),gender(P=0.039),diabetes(P=0.003),history of infectious diseases(P=0.02),and duration of mask replacement(Pbeijing,***,an increased isolation rate of Corynebacterium and Micrococcus is detected,suggesting a possible change in the mic

关键词： conjunctival microbiota 16S rDNA middle-aged and elderly population mask cataract surgery

Advances in the Development of Gradient Scaffolds Made of Nano‑Micromaterials for Musculoskeletal Tissue Regeneration

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Nano-Micro Letters 2025年第3期17卷 455-500页

作者： Lei Fang Xiaoqi Lin Ruian Xu Lu Liu Yu Zhang Feng Tian Jiao Jiao Li Jiajia Xue beijing laboratory of Biomedical Materials Beijing University of Chemical TechnologyBeijing 100029People’s Republic of China State key laboratory of Organic‑Inorganic Composites Beijing University of Chemical TechnologyBeijing 100029People’s Republic of China School of Biomedical Engineering Faculty of Engineering and ITUniversity of Technology SydneySydneyNSW 2007Australia

The intricate hierarchical structure of musculoskeletal tissues,including bone and interface tissues,necessitates the use of complex scaffold designs and material structures to serve as tissue-engineered *** has led to growing interest in the development of gradient bone scaffolds with hierarchical structures mimicking the extracellular matrix of native tissues to achieve improved therapeutic *** on the anatomical characteristics of bone and interfacial tissues,this review provides a summary of current strategies used to design and fabricate biomimetic gradient scaffolds for repairing musculoskeletal tissues,specifically focusing on methods used to construct compositional and structural gradients within the *** latest applications of gradient scaffolds for the regeneration of bone,osteochondral,and tendon-to-bone interfaces are ***,the current progress of testing gradient scaffolds in physiologically relevant animal models of skeletal repair is discussed,as well as the challenges and prospects of moving these scaffolds into clinical application for treating musculoskeletal injuries.

关键词： Gradient scaffolds Musculoskeletal tissues Advanced manufacturing Biomaterials Tissue regeneration