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Inherently Chiral and Symmetrical Heteroatom-Doped Zigzag-Type Hydrocarbon Belts

CCS Chemistry 2024年第5期6卷 1198-1210页

作者： Xue-Yuan Wang Xin-Yu Zhang Shuo Tong Qing-Hui Guo mei-ling Tan cheng-Jun Li mei-Xiang Wang Key Laboratory of Bioorganic Phosphorous Chemistry and Chemical Biology(Ministry of Education) Department of ChemistryTsinghua UniversityBeijing 100084

hydrocarbon belts due to their potential applications in carbon *** contrast,heteroatomembedded zigzag hydrocarbon belts as advanced design strategies with fascinating structures and desirable,unique properties have remained largely unexplored,and inherently chiral ones are ***,we report the synthesis of a diversity of symmetric and highly enantiopure inherently chiral O-and N-doped zigzag-type hydrocarbon belts starting from strainless macrocycles based on fjord-stitching *** readily available pertriflated resorcin[6]arene underwent partial hydrolyses and intramolecular S_(N)Ar reactions to form a calix[3](9H-xanthene)derivative and a prochiral half-belt *** transformations of calix[3](9H-xanthene)into C_(3v)-symmetric molecular belts were achieved by closing the rest of the fjords with triple intramolecular S_(N)Ar reactions and Yamamoto homo coupling reactions,as well as palladiumcatalyzed intermolecular acridination reactions with primary *** prochiral half-belt underwent enantioselective desymmetrizative mono-acridination to afford an inherently chiral N,O_(4)-bridged pseudo-belt with an enantiomeric excess(ee)value of>99%under the catalysis of Pd(OAc)_(2)and(R)-*** closure reactions of the pseudo-belt produced diverse heteroatom-inlayed zigzag-type hydrocarbon belts of inherent ***,we showed the unique cavity structures of the belts and demonstrated interesting chiroptic properties of the inherently enantiopure chiral *** research opens the door for the exploration of novel and sophisticated symmetric and inherently chiral molecular nanobelt structures with outstanding physical and chemical properties,as well as potential applications.

关键词： zigzag-type molecular belt heterocycle chiroptical property fjord-stitching strategy resorcinarene

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Cosmological interpretation for the stochastic signal in pulsar timing arrays

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Science China(Physics,Mechanics & Astronomy) 2024年第4期67卷 43-50页

作者： Yu-mei Wu Zu-cheng Chen Qing-Guo Huang School of Fundamental Physics and Mathematical Sciences Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of SciencesHangzhou 310024China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100049China Department of Astronomy Beijing Normal UniversityBeijing 100875China Advanced Institute of Natural Sciences Beijing Normal UniversityZhuhai 519087China Department of Physics and Synergistic Innovation Center for Quantum Effects and Applications Hunan Normal UniversityChangsha 410081China CAS Key Laboratory of Theoretical Physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China

The pulsar timing array(PTA)collaborations have recently reported compelling evidence for a stochastic signal consistent with a gravitational-wave *** this paper,we combine the latest data sets from NANOGrav,PPTA,and EPTA to explore cosmological interpretations for the PTA signal from first-order phase transitions,domain walls,and cosmic strings,*** find that the domain wall model is strongly disfavored with the Bayes factors compared with the first-order phase transitions and cosmic strings being 1/90 and 1/189,respectively,breaking the degeneracy among these models in individual data *** also find that:(1)a strong phase transition at temperatures below the electroweak scale is favored,and the bubble collisions make the dominant contribution to the energy density spectrum;(2)a small reconnection probability p<1.55×10^(-1)allowed by strings in(super)string theory is favored at the 95%confidence level,and ground-based detectors can further constrain the parameter space.

关键词： puslar timing arrays gravitational-wave background first-order phase transitions domain walls cosmic strings

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Clinical analysis of multiple primary gastrointestinal malignant tumors:A 10-year case review of a single-center

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World Journal of Gastrointestinal Oncology 2024年第4期16卷 1204-1212页

作者： cheng-Lou Zhu ling-Zhi Peng The First School of Clinical Medicine Lanzhou UniversityLanzhou 730000Gansu ProvinceChina Department of Surgical Oncology Gansu Provincial HospitalLanzhou 730000Gansu ProvinceChina

BACKGROUND Multiple primary malignant tumors(MPMTs)was first described by Billroth as early as 1889,with the first report published by Warren and Gates in *** then,numerous cases have been reported.A literature review of 1104269 patients with cancer revealed that the incidence of MPMTs ranged from 0.73 to 11.7%.In recent years,however,there has been a significant upward trend in the incidence of this phenomenon,which may be associated with many different factors,including the advancement of modern diagnostic procedures facilitating the examination and diagnosis of more MPMTs,increased exposure to chemotherapy and radiotherapy that exacerbate the risk of new malignant tumors in patients with cancer,and prolonged survival of patients with cancer allowing sufficient time for the development of new primary *** To analyze the incidence,clinical features,treatment factors,prevalence,and prognosis of patients with MPMTs in the gastrointestinal tract treated in a single ***,we analyzed the different tumor combinations,time interval between the occurrence of tumors,and *** This retrospective cohort study analyzed 8059 patients with pathologically confirmed gastrointestinal malignant tumors treated at the Gansu Province Hospital in Lanzhou,Gansu,China between June 2011 and June *** these,85 patients had *** clinical features,treatment factors,prevalence,and prognosis of this latter cohort were *** The incidence of MPMTs in patients with gastrointestinal malignant tumors was 1.05%(85/8059),including 83 double primary malignant tumors and two triple primary malignant tumors of which 57(67.06%)were synchronous MPMTs(SMPMTs)and 28(32.94%)were metachronous MPMTs(MMPMTs).The most frequent associations were found between the rectum colon cancers within the SMPMT category and the gastric-colon cancers within the MMPMT *** the MMPMTs,the median interval was 53 *** overall 1-,3-and 5-year survival rates f

关键词： Multiple primary malignant tumors Clinical characteristics Gastrointestinal tract Prognosis Epidemiology

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Insight into Lithium–sulfur batteries performance enhancement: from metal nanoparticles to metal nanoclusters to single metal atoms

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Tungsten 2024年第3期6卷 504-521页

作者： Shuang Ma Qing-ling Ruan Xue-cheng Liu Gui-Jun Zhu Die Yuan ling-Qiao Hu Yu-mei Huang Xing-Xing Gu Chongqing Key Laboratory of Catalysis and New Environmental Materials College of Environment and Resources Chongqing Technology and Business University National Research Base of Intelligent Manufacturing Service Chongqing Technology and Business University

Lithium-sulfur(Li-S) batteries have attracted much attention and developed rapidly in recent years due to their high energy density,low cost,and ***,its commercialization process still encounters various *** them,the sulfur cathode is easy to dissolve and shuttle,resulting in the loss of active substances and the severe growth of lithium anode dendrites,which is one of the biggest *** the redox conversion kinetics of sulfur cathode is expected to fundamentally alleviate the shuttle phenomenon of poly ***,this paper reviews the effects of metal nanoparticles to metal nanoclusters to metal single-atom catalysts on improving the redox of Li-S batteries,to let researchers better understand the size effect on the kinetics of sulfur cathodes in Li-S batteries,which will provide important guidance for the future large-scale commercialization of Li-S batteries.

关键词： Lithium–sulfur batteries Metal nanoparticles Metal nanoclusters Metal single atoms Size effects

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Application of total keratometry in ten intraocular lens power calculation formulas in highly myopic eyes

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Eye and Vision 2024年第2期10卷 22-30页

作者： ling Wei Kaiwen cheng Wenwen He Xiangjia Zhu Yi Lu Department of Ophthalmology and Eye Institute Eye and ENT Hospital of Fudan UniversityShanghai 200031China Key Laboratory of Myopia(Fudan University)Key Laboratory of MyopiaShanghai Key Laboratory of Visual Impairment and Restoration National Health CommissionChinese Academy of Medical ScienceShanghai 200031China State Key Laboratory of Medical Neurobiology Fudan UniversityShanghai 200031China

Background:The accuracy of using total keratometry(TK)value in recent IOL power calculation formulas in highly myopic eyes remained ***:Highly myopic patients who underwent uneventful cataract surgery were prospectively enrolled in this prospective comparative *** one month postoperatively,standard deviation(SD)of the prediction errors(PEs),mean and median absolute error(MedAE)of 103 highly myopic eyes were back-calculated and compared among ten formulas,including XGboost,RBF 3.0,Kane,Barrett Universal II,Emmetropia Verifying Optical 2.0,Cooke K6,Haigis,SRK/T,and Wang-Koch modifications of Haigis and SRK/T formulas,using either TK or standard keratometry(K)***:In highly myopic eyes,despite good agreement between TK and K(P>0.05),larger differences between the two were associated with smaller central corneal thickness(P0.05),which both presented smaller MedAEs than others(all P0.05),and statistically larger percentages than the other eight formulas(P<0.05).Conclusions:Highly myopic eyes with thinner corneas tend to have larger differences between TK and *** XGboost enhancement calculator and RBF 3.0 formula using TK showed the most promising outcomes in highly myopic eyes.

关键词： High myopia Total keratometry Cataract surgery IOL power calculation

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Small tracking error correction for moving targets of intelligent electro-optical detection systems

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Frontiers of Mechanical Engineering 2024年第2期19卷 29-44页

作者： cheng SHEN Zhijie WEN Wenliang ZHU Dapeng FAN Mingyuan ling College of Intelligence Science and Technology National University of Defense TechnologyChangsha 410073China

Small tracking error correction for electro-optical systems is essential to improve the tracking precision of future mechanical and defense *** threats,such as“low,slow,and small(LSS)”moving targets,pose increasing challenges to *** core goal of this work is to address the issues,such as small tracking error correction and aiming control,of electro-optical detection systems by using mechatronics drive modeling,composite velocity–image stability control,and improved interpolation filter design.A tracking controller delay prediction method for moving targets is proposed based on the Euler transformation model of a two-axis,two-gimbal cantilever beam coaxial *** tracking error formation is analyzed in detail to reveal the scientific mechanism of composite control between the tracking controller’s feedback and the motor’s velocity–stability *** improved segmental interpolation filtering algorithm is established by combining line of sight(LOS)position correction and multivariable typical tracking fault ***,a platform with 2 degrees of freedom is used to test the *** LSS moving target shooting object with a tracking distance of S=100 m,target board area of A=1 m^(2),and target linear velocity of v=5 m/s is *** show that the optimal method’s distribution probability of the tracking error in a circle with a radius of 1 mrad is 66.7%,and that of the traditional method is 41.6%.Compared with the LOS shooting accuracy of the traditional method,the LOS shooting accuracy of the optimized method is improved by 37.6%.

关键词： electro-optical detection system small tracking error moving target visual servo aiming contro

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One-year observation of the mixing states of oxygenated organics-containing single particles in Guangzhou,China

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Frontiers of Environmental Science & Engineering 2024年第5期18卷 155-169页

作者： Liyuan Mao Suxia Yang Xiaoya cheng Sulin Liu Duanying Chen Zhen Zhou mei Li chenglei Pei Chunlei cheng Institute of Mass Spectrometry and Atmospheric Environment Guangdong Provincial Engineering Research Center for the On-line Source Apportionment System of Air PollutionJinan UniversityGuangzhou510632China Guangdong-Hongkong-Macao Joint Laboratory of Collaborative Innovation for Environmental Quality Guangzhou510632China Guangzhou Research Institute of Environment Protection Co. Ltd.Guangzhou510620China Guangzhou Ecological and Environmental Monitoring Center of Guangdong Province Guangzhou510030China State Key Laboratory of Marine Resource Utilization in South China Sea Hainan UniversityHaikou570228China State Key Laboratory of Loess and Quaternary Geology Institute of Earth EnvironmentChinese Academy SciencesXi’an710061China

Oxygenated organic molecules(OOMs)play an important role in the formation of secondary organic aerosols(SOAs),but the mixing states of OOMs are still *** study investigates the mixing states of OOM-containing single particles from the measurements taken using a single particle aerosol mass spectrometer in Guangzhou,China in ***,the particle counts of OOM particles and the mass concentration of secondary organic carbon(SOC)exhibited similar temporal trends throughout the entire *** OOM particles were consistently enriched in secondary ions,including ^(16)O^(−),^(26)CN^(−),^(46)NO_(2)^(−),^(62)NO_(3)^(−),and ^(97)HSO_(4)^(−).In contrast,the number fractions and diurnal patterns of OOM particles among the total detected particles showed similar distributions in August and October;however,the SOC ratios in fine particulate matter were quite different,suggesting that there were different mixing states of single-particle oxygenated *** addition,further classification results indicated that the OOM particles were more aged in October than August,even though the SOC ratios were higher in ***,the distribution of hydrocarbon fragments exhibited a notable decrease from January to October,emphasizing the more aged state of the organics in *** addition,the sharp increase in elemental carbon(EC)-OOM particles in the afternoon in October suggests the potential role of EC in the aging process of ***,in contrast to the bulk analysis of SOC mass concentration,the mixing states of the OOM particles provide insights into the formation process of SOAs in field studies.

关键词： Oxygenated organics Single particles Mixing state Secondary formation Photochemistry

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Thermal runaway evolution of a 280 Ah lithium-ion battery with LiFePO_(4) as the cathode for different heat transfer modes constructed by mechanical abuse

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Journal of Energy Chemistry 2024年第6期93卷 32-45,I0002页

作者： Zhixiang cheng chengdong Wang Wenxin mei Peng Qin Junyuan Li Qingsong Wang State Key Laboratory of Fire Science University of Science and Technology of ChinaHefei 230026AnhuiChina

Lithium iron phosphate batteries have been increasingly utilized in recent years because their higher safety performance can improve the increasing trend of recurring thermal runaway ***,the safety performance and mechanism of high-capacity lithium iron phosphate batteries under internal short-circuit challenges remain to be *** work analyzes the thermal runaway evolution of high-capacity LiFePO_(4) batteries under different internal heat transfer modes,which are controlled by different penetration *** penetration cases involving complete penetration and incomplete penetration were detected during the test,and two modes were performed incorporating nails that either remained or were removed after penetration to comprehensively reveal the thermal runaway mechanism.A theoretical model of microcircuits and internal heat conduction is also *** results indicated three thermal runaway evolution processes for high-capacity batteries,which corresponded to the experimental results of thermal equilibrium,single thermal runaway,and two thermal runaway *** difference in heat distribution in the three phenomena is determined based on the microstructure and material structure near the *** controlling the heat dissipation conditions,the time interval between two thermal runaway events can be delayed from 558 to 1417 s,accompanied by a decrease in the concentration of in-situ gas production during the second thermal runaway event.

关键词： Lithium-ion battery safety Micro short-circuit cell Heat transfer modes Internal short circuit Nail-penetration test

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Time evolutions of scalar field perturbation in Schwarzschild de-Sitter black hole from Einstein-scalar–Gauss–Bonnet theory

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Communications in Theoretical Physics 2024年第1期76卷 76-81页

作者： cheng Xu Zhen-Hao Yang Xiao-mei Kuang Rui-Hong Yue Center for Gravitation and Cosmology College of Physical Science and TechnologyYangzhou UniversityYangzhou225009China

The scalar-free black hole could be unstable against the scalar field perturbation when it is coupled to a Gauss–Bonnet(GB)invariant in a special *** is known that the tachyonic instability in this scenario is triggered by the sufficiently strong GB *** this paper,we focus on the time domain analysis of massive scalar field perturbation around the Schwarzschild de-Sitter black hole in Einstein-scalar–Gauss–Bonnet *** analyzing the scalar field propagation,we find that the scalar field will finally grow when the GB coupling is large *** could lead to the instability of the background black ***,we demonstrate how the mass of the scalar field and the GB coupling strength affect the onset of tachyonic instability.

关键词： black hole perturbation scalar-Einstein-Gauss-Bonnet gravity time domain evolution me

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Emerging role of vitamin D_(3)in alleviating intestinal structure injury caused by Aeromonas hydrophila in grass carp(Ctenopharyngodon idella)

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Animal Nutrition 2024年第1期16卷 202-217页

作者： Yao Zhang Xiao-Qiu Zhou Wei-Dan Jiang Pei Wu Yang Liu Hong-mei Ren Lu Zhang Hai-Feng Mi ling Tang cheng-Bo Zhong Lin Feng Animal Nutrition Institute Sichuan Agricultural UniversityChengduChina Fish Nutrition and Safety Production University Key Laboratory of Sichuan Province Sichuan Agricultural UniversityChengduChina Key Laboratory for Animal Disease-Resistant Nutrition of China Ministry of Education Sichuan Agricultural UniversityChengduChina Healthy Aquaculture Key Laboratory of Sichuan Province Tongwei Co.Ltd.ChengduChina Sichuan Animal Science Academy Sichuan Animtech Feed Co.Ltd.ChengduChina

Bacterial pathogens destroy the structural integrity of functional organs in fish,leading to severe challenges in the aquaculture *** D_(3)(VD_(3))prevents bacterial infections and strengthens immune system function via vitamin D receptor(VDR).However,the correlation between VD_(3)/VDR and the structural integrity of functional organs remains *** study aimed to investigate the influence of VD_(3)supplementation on histological characteristics,apoptosis,and tight junction characteristics in fish intestine during pathogen infection.A total of 540 healthy grass carp(257.24±0.63 g)were fed different levels of VD_(3)(15.2,364.3,782.5,1,167.9,1,573.8,and 1,980.1 IU/kg)for 70 ***,fish were challenged with Aeromonas hydrophila,a pathogen that causes intestinal *** present study demonstrated that optimal supplementation with VD_(3)(1)alleviated intestinal structural damage,and inhibited oxidative damage by reducing levels of oxidative stress biomarkers;(2)attenuated excessive apoptosisrelated death receptor and mitochondrial pathway processes in relation to p38 mitogen-activated protein kinase signaling(Pling(P<0.05);and(4)elevated VDR isoform expression in fish intestine(P<0.05).Overall,the results demonstrated that VD_(3)alleviates oxidative injury,apoptosis,and the destruction of tight junction protein under pathogenic infection,thereby strengthening pathogen defenses in the *** finding supports the rationale for VD_(3)intervention as an essential practice in sustainable aquaculture.

关键词： Aeromonas hydrophila Antibacterial property Grass carp(Ctenopharyngodon idella) Intestinal health Vitamin D_(3)

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