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Effect of aspect ratio of elliptical stirred vessel on mixing time and flow field characteristics in the absence of baffles

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Chinese Journal of Chemical Engineering 2024年第1期65卷 63-74页

作者： yuan Yao Peiqiao Liu qian Zhang Zequan Li Benjun Xi Changyuan Tao Yundong Wang Zuohua Liu School of Chemistry and Chemical Engineering Chongqing UniversityChongqing 400044China Hubei Three Gorges Laboratory Yichang 443007China Department of Chemical Engineering Tsinghua UniversityBeijing 100084China

Elliptical tanks were used as an alternative to circular tanks in order to improve mixing efficiency and reduce mixing time in unbaffled stirred tanks(USTs). Five different aspect ratios of elliptical vessels were designed to compare their mixing time and flow field. Computational fluid dynamics(CFD) simulations were performed using the k–ε model to calculate the mixing time and simulate turbulent flow field features, such as streamline shape, velocity distribution, vortex core region distribution, and turbulent kinetic energy(TKE) transfer. Visualization was also carried out to track the tinctorial evolution of the liquid phase. Results reveal that elliptical stirred tanks can significantly improve mixing performance in USTs. Specifically, the mixing time at an aspect ratio of 2.00 is only 45.3% of the one of a circular stirred tank. Furthermore, the secondary flow is strengthened and the vortex core region increases with the increase of aspect ratio. The axial velocity is more sensitive to the aspect ratio than the circumferential and radial velocity. Additionally, the TKE transfer in elliptical vessels is altered. These findings suggest that elliptical vessels offer a promising alternative to circular vessels for enhancing mixing performance in USTs.

关键词： Mixing time CFD Stirred tank Secondary flow Mixing performance

Kinetics insights into size effects of carbon nanotubes'growth and their supported platinum catalysts for 4,6-dinitroresorcinol hydrogenation

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Chinese Journal of Chemical Engineering 2024年第8期72卷 133-140页

作者： Yan Zhang Xiangxue Zhang Keng Sang Wenyao Chen Gang qian Jing Zhang Xuezhi Duan Xinggui Zhou Weikang yuan State Key Laboratory of Chemical Engineering East China University of Science and TechnologyShanghai 200237China

Size effects are a well-documented phenomenon in heterogeneous catalysis,typically attributed to alterations in geometric and electronic *** this study,we investigate the influence of catalyst size in the preparation of carbon nanotube(CNT)and the hydrogenation of 4,6-dinitroresorcinol(DNR)using Fe_(2)O_(3)and Pt catalysts,*** Fe_(2)O_(3)/Al_(2)O_(3)catalysts were synthesized for CNT growth through catalytic chemical vapor *** findings reveal a significant influence of Fe_(2)O_(3)nanoparticle size on the structure and yield of ***,CNT produced with Fe_(2)O_(3)/Al_(2)O_(3)containing 28%(mass)Fe loading exhibits abundant surface defects,an increased area for metal-particle immobilization,and a high carbon *** makes it a promising candidate for DNR *** this catalyst support,we further investigate the size effects of Pt nanoparticles on DNR *** Pt catalysts demonstrate a preference for 4,6-diaminoresorcinol generation at(100)sites,whereas smaller Pt catalysts are more susceptible to electronic *** kinetics insights obtained from this study have the potential to pave the way for the development of more efficient catalysts for both CNT synthesis and DNR hydrogenation.

关键词： Kinetics Size effects Catalytic hydrogenation Active site

Monte Carlo method for evaluation of surface emission rate measurement uncertainty

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Nuclear Science and Techniques 2024年第7期35卷 126-136页

作者： yuan-Qiao Li Min Lin Li-Jun Xu Rui Luo Yu-He Zhang qian-Xi Ni Yun-Tao Liu China Institute of Atomic Energy Beijing102413China National Key Laboratory for Metrology and Calibration Techniques Beijing102413China Department of Radiation Oncology Hunan Cancer HospitalChangsha410031China The Affiliated Cancer Hospital of Xiangya School of Medicine Central South UniversityChangsha410031China

The aim of this study is to evaluate the uncertainty of 2πα and 2πβ surface emission rates using the windowless multiwire proportional counter *** study used the Monte Carlo method (MCM) to validate the conventional Guide to the Expression of Uncertainty in Measurement (GUM) method.A dead time measurement model for the two-source method was established based on the characteristics of a single-channel measurement system,and the voltage threshold correction factor measurement function was indirectly obtained by fitting the threshold correction *** uncertainty in the surface emission rate was calculated using the GUM method and the law of propagation of *** MCM provided clear definitions for each input quantity and its uncertainty distribution,and the simulation training was realized with a complete and complex mathematical *** results of the surface emission rate uncertainty evaluation for four radioactive plane sources using both methods showed the uncertainty’s consistency E_(n)<0.070 for the comparison of each source,and the uncertainty results of the GUM were all lower than those of the ***,the MCM has a more objective evaluation process and can serve as a validation tool for GUM results.

关键词： Surface emission rate Monte Carlo method Metrology Probability distribution function Dead time Low-energy loss correction Least-squares method

Chemoradiotherapy plus tislelizumab for mismatch repair proficient rectal cancer with supraclavicular lymph node metastasis:A case report

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World Journal of Gastrointestinal Oncology 2024年第5期16卷 2219-2224页

作者： Wen-Tao Zhong yuan Lv qian-Yu Wang Ran An Gang Chen Jun-Feng Du The Second School of Clinical Medicine Southern Medical UniversityGuangzhou 510515Guangdong ProvinceChina Department of General Surgery The 7^(th)Medical Center of PLA General HospitalBeijing 100700China Department of Pathology The 7^(th)Medical Center of PLA General HospitalBeijing 100700China

BACKGROUND According to the latest report,colorectal cancer is still one of the most prevalent cancers,with the third highest incidence and mortality *** of advanced rectal cancer with distant metastases is usually unsatisfactory,especially for mismatch repair proficient(pMMR)rectal cancer,which leads to poor prognosis and *** SUMMARY We report a case of a pMMR rectal adenocarcinoma with metastases of multiple lymph nodes,including the left supraclavicular lymph node,before treatment in a 70-year-old *** received full courses of chemoradiotherapy(CRT)followed by 4 cycles of programmed death 1 inhibitor Tislelizumab,and a pathologic complete response(pCR)was achieved,and the lesion of the left supraclavicular lymph node also *** pMMR advanced rectal cancer with preserved intact distant metastatic lymph nodes may benefit from full-course CRT combined with immunotherapy.

关键词： Rectal cancer Metastasis Chemoradiotherapy Immunotherapy Prognosis Case report

Copper-catalyzed conjugate addition of allene-derived nucleophiles to alkenyl-substituted carboxamides

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Chinese Chemical Letters 2024年第3期35卷 239-242页

作者： Bin Fu Yue Zhao Xiuping yuan Yanfei Li Jianjun Yin Simin Wang Tao Xiong qian Zhang Jilin Province Key Laboratory of Organic Functional Molecular Design&Synthesis Department of ChemistryNortheast Normal UniversityChangchun 130024China State Key Laboratory of Organometallic Chemistry Shanghai Institute of Organic ChemistryChinese Academy of SciencesShanghai 200032China School of Chemistry and Environmental Engineering Changchun University of Science and TechnologyChangchun 130012China

Catalytic Michael addition reaction represents a fundamental importance in organic synthetic *** corresponding conversions toward intrinsically low reactive enamide remains an ongoing *** herein report a copper-catalyzed conjugate addition of allenes toβ-substituted alkenyl amides,one of the most challenging Michael *** present method utilizes readily available allenes as the latent carbon-based nucleophiles and simple,commonβ-substituted alkenyl amides as starting materials,unlike previous methods that usually preinstall an activating group to improve the reactivity of amide or uses highly reactive stoichiometric quantities of ***,this approach shows good functional group compatibility and can be implemented under mild reaction conditions with excellent level of chemo-and regioselectivities.

关键词： CuH catalysis Allenes Unsaturated amide Conjugate addition Regioselectivity

Engineering and understanding SnS_(0.5)Se_(0.5)@N/S/Se triple-doped carbon nanofibers for enhanced sodium-ion batteries

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Chinese Chemical Letters 2024年第4期35卷 226-230页

作者： Fanjun Kong Yixin Ge Shi Tao Zhengqiu yuan Chen Lu Zhida Han Lianghao Yu Bin qian School of Electronic and Information Engineering Changshu Institute of TechnologyChangshu 215500China Key Laboratory of Spin Electron and Nanomaterials of Anhui Higher Education Institutes Suzhou UniversitySuzhou 234000China Far East Holding Group Co. Ltd.Yixing 214200China

Tin-based chalcogenides have attracted tremendous attention as an anode material for sodium storage owing to their unique structure and high theoretical capacity. Unfortunately, the large volume change and poor conductivity lead to sluggish reaction kinetics and poor cycling performance. Herein, SnS_(0.5)Se_(0.5)nanoparticles coupled with N/S/Se triple-doped carbon nanofibers(SnS_(0.5)Se_(0.5)@NSSe-C) are designed and synthesized through electrospinning and annealing process. Benefiting from the synergistic effects of SnS_(0.5)Se_(0.5)and NSSe-C, the SnS_(0.5)Se_(0.5)@NSSe-C nanofibers exhibit a high reversible capacity and ultralong cycle life at higher current density for sodium-ion batteries. Furthermore, the sodium storage mechanism and electrochemical reaction kinetics of the SnS_(0.5)Se_(0.5)@NSSe-C composite are characterized by the in-situ measurements. The theoretical calculations further reveal the structural advantages of SnS_(0.5)Se_(0.5)@NSSeC composite, which exhibits a high adsorption energy of Na+. This work can provide a novel idea for the synthesis of ternary tin-based chalcogenides and is beneficial for the investigation of their reaction kinetics.

关键词： SnS_(0.5)Se_(0.5) Carbon nanofibers Doping Density functional theory Sodium ion batteries

Mesenchymal stromal cells modulate unfolded protein response and preserve β-cell mass in type 1 diabetes

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BIOCELL 2024年第7期48卷 1115-1126页

作者： SIyuan LIU yuan ZHAO YU YU DOU YE qian WANG ZHAOYAN WANG ZUO LUAN Department of Pediatrics The Sixth Medical CenterChinese PLA General HospitalBeijing100037China

Introduction:Transplantation of mesenchymal stromal cells(MSCs)is a promising therapy for type 1 diabetes(T1D).However,whether the infused MSCs affect the endoplasmic reticulum stress or subsequent unfolded protein response inβcells remains ***:To investigate this,we induced early-onset T1D in non-obese diabetic mice using ***,T1D mice were randomly assigned to receive either MSCs or phosphate-buffered *** observed the in vivo homing of MSCs and assessed their effectiveness by analyzing blood glucose levels,body weight,histopathology,pancreatic protein expression,and serum levels of cytokines,proinsulin,and ***:Infused MSCs were found in the lungs,liver,spleen,and pancreas of T1D *** exhibited various effects,including reducing blood glucose levels,regulating immunity,inhibiting inﬂammation,increasingβ-cell areas,and reducing the expression of key proteins in the unfolded protein response *** serum proinsulin and C-peptide levels were signiﬁcantly higher in the MSCs treatment group than in the T1D model ***,there was no signiﬁcant difference in the biomarker ofβ-cell endoplasmic reticulum stress,the ratio of fasting serum proinsulin to C-peptide,between the two ***:Ourﬁndings reveal that MSCs infusion does not alleviate endoplasmic reticulum stress inβcells directly but modulates the unfolded protein response pathway to preserveβ-cell mass and function in T1D mice.

关键词： Type 1 diabetes Mesenchymal stromal cells Endoplasmic reticulum stress Unfolded protein response Non-obese diabetic mice

Highly transparent anti-reflection coating enhances the underwater efficiency and stability of perovskite solar modules

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Nano Research 2024年第9期17卷 8126-8133页

作者： Feng qian Shihao yuan Ting Zhang Lei Wang Xiaobo Li Hualin Zheng Qien Xu Zhi David Chen Shibin Li School of Optoelectronic Science and Engineering University of Electronic Science and Technology of ChinaChengdu 610054China Department of Electrical and Computer Engineering and Center for Nanoscale Science and Engineering University of KentuckyLexingtonKentucky 40506USA

Perovskite solar cells have shown great potential in the field of underwater solar cells due to their excellent optoelectronic properties;however,their underwater performance and stability still hinder their practical *** this research,a 1H,1H,2H,2H-heptadecafluorodecyl acrylate(HFDA)anti-reflection coating(ARC)was introduced as a high-transparent material for encapsulating perovskite solar modules(PSMs).Optical characterization results revealed that HFDA can effectively reduce reflection of light below 800 nm,aiding in the absorption of light within this wavelength range by underwater solar ***,a remarkable efficiency of 14.65%was achieved even at a water depth of 50 ***,the concentration of Pb^(2+)for HFDA-encapsulated film is significantly reduced from 186 to 16.5 ppb after being immersed in water for 347 ***,the encapsulated PSMs still remained above 80%of their initial efficiency after continuous underwater illumination for 400 ***,being exposed to air,the encapsulated PSMs maintained 94%of their original efficiency after 1000 h light *** highly transparent ARC shows great potentials in enhancing the stability of perovskite devices,applicable not only to underwater cells but also extendable to land-based photovoltaic devices.

关键词： underwater photovoltaics perovskite solar modules anti-reflection coating underwater stability

Construction of the underlying circRNA-miRNA-mRNA regulatory network and a new diagnostic model in ulcerative colitis by bioinformatics analysis

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World Journal of Clinical Cases 2024年第9期12卷 1606-1621页

作者： Yu-Yi yuan Hui Wu qian-Yun Chen Heng Fan Bo Shuai Department of Integrated Traditional Chinese and Western Medicine Union HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430022Hubei ProvinceChina

BACKGROUND Circular RNAs(circRNAs)are involved in the pathogenesis of many diseases through competing endogenous RNA(ceRNA)regulatory *** To investigate a circRNA-related ceRNA regulatory network and a new predictive model by circRNA to understand the diagnostic mechanism of circRNAs in ulcerative colitis(UC).METHODS We obtained gene expression profiles of circRNAs,miRNAs,and mRNAs in UC from the Gene Expression Omnibus *** circRNA-miRNA-mRNA network was constructed based on circRNA-miRNA and miRNA-mRNA *** enrichment analysis was performed to identify the biological mechanisms involved in *** identified the most relevant differential circRNAs for diagnosing UC and constructed a new predictive nomogram,whose efficacy was tested with the C-index,receiver operating characteristic curve(ROC),and decision curve analysis(DCA).RESULTS A circRNA-miRNA-mRNA regulatory network was obtained,containing 12 circRNAs,three miRNAs,and 38 *** optimal prognostic-related differentially expressed circRNAs,hsa_circ_0085323 and hsa_circ_0036906,were included to construct a predictive *** model showed good discrimination,with a C-index of 1(>0.9,high accuracy).ROC and DCA suggested that the nomogram had a beneficial diagnostic *** This novel predictive nomogram incorporating hsa_circ_0085323 and hsa_circ_0036906 can be conveniently used to predict the risk of *** circRNa-miRNA-mRNA network in UC could be more clinically significant.

关键词： Circular RNAs RNA regulatory network Ulcerative colitis New predictive model Bioinformatics Diagnose