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Science China Chemistry 2024年第2期67卷 576-586页

作者： Xiao-Bao Wu Jun-Xiu Shi yi-Ming Ou Hua-Jie Jiang yi-Jun Fang Qi-Ming Wang Quan Gao Jie Yu Department of Applied Chemistry Anhui Province Engineering Laboratory for Green Pesticide Development and ApplicationAnhui Province Key Laboratory of Crop Integrated Pest ManagementAnhui Agricultural UniversityHefei230036China

A privileged strategy has been developed for the precise construction of enantioenriched azaspiro polycyclic *** diverse azaspiro polycycles bearing multiple contiguous stereocenters are obtained with excellent results(up to 99:1.e.r.,>95:5 d.r.) via sequential enantioselective four-component Ugi reactions/post-Ugi transformations with substrates containing prerequisite functional groups in the presence of anionic stereogenic-at-cobalt(Ⅲ) complexes.

关键词： asymmetric catalysis post-Ugi transformation anionic stereogenic-at-cobalt(Ⅲ)complex azaspiro polycyclic scaffold one-pot synthesis

Analog spatiotemporal feature extraction for cognitive radio-frequency sensing with integrated photonics

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Light(Science & Applications) 2024年第3期13卷 478-487页

作者： Shaofu Xu Binshuo Liu Sicheng yi Jing Wang Weiwen Zou State Key Laboratory of Advanced Optical Communication Systems and Networks Intelligent Microwave Lightwave Integration Innovation Center(imLic)Department of Electronic EngineeringShanghai Jiao Tong UniversityShanghaiChina

Analog feature extraction(AFE)is an appealing strategy for low-latency and efficient cognitive sensing systems since key features are much sparser than the Nyquist-sampled ***,applying AFE to broadband radio-frequency(RF)scenarios is challenging due to the bandwidth and programmability bottlenecks of analog electronic ***,we introduce a photonics-based scheme that extracts spatiotemporal features from broadband RF signals in the analog *** feature extractor structure inspired by convolutional neural networks is implemented on integrated photonic circuits to process RF signals from multiple antennas,extracting valid features from both temporal and spatial *** of the tunability of the photonic devices,the photonic spatiotemporal feature extractor is trainable,which enhances the validity of the extracted ***,a digital-analog-hybrid transfer learning method is proposed for the effective and low-cost training of the photonic feature *** validate our scheme,we demonstrate a radar target recognition task with a 4-GHz instantaneous *** results indicate that the photonic analog feature extractor tackles broadband RF signals and reduces the sampling rate of analog-to-digital converters to 1.4 of the Nyquist sampling while maintaining a high target recognition accuracy of 97.5%.Our scheme offers a promising path for exploiting the AFE strategy in the realm of cognitive RF sensing,with the potential to contribute to the efficient signal processing involved in applications such as autonomous driving,robotics,and smart factories.

关键词： scheme driving smart

Free radicals trigger the closure of open pores in lignin-derived hard carbons toward improved sodium-storage capacity

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Journal of Energy Chemistry 2024年第7期94卷 551-559页

作者： Wen-Jun Ji Zong-Lin yi Ming-Xin Song Xiao-Qian Guo yi-Lin Wang yi-Xuan Mao Fang-Yuan Su Jing-Peng Chen Xian-Xian Wei Li-Jing Xie Cheng-Meng Chen CAS Key Laboratory of Carbon Materials Institute of Coal ChemistryChinese Academy of SciencesTaiyuan 030001ShanxiChina University of Chinese Academy of Sciences Beijing 100049China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China School of Environment and Safety Taiyuan University of Science and TechnologyTaiyuan 030001ShanxiChina

The chemical activation of various precursors is effective for creating additional closed pores in hard carbons for sodium ***,the formation mechanism of closed pores under the influence of pore-forming agents is not well ***,an effective chemical activation followed by a high-temperature self-healing strategy is employed to generate interconnected closed pores in lignin-derived hard carbon(HCs).By systematic experimental design combined with electron paramagnetic res-onance spectroscopy,it can be found that the content of free radicals in the carbon matrix influences the closure of open pores at high *** high activation temperature(>700 C)leads to a low free radical concentration,making it difficult to achieve self-healing of open pores at high *** activation at 700°C,a balance between pore making and self-healing is achieved in the final hard carbon.A large number of free radicals triggers rapid growth and aggregation of carbon microcrys-tals,blocking pre-formed open micropores and creating additional interconnected closed pores in as-obtained hard *** a result,the optimized carbon anode(LK-700-1.00)delivers a high reversible capacity of 330.8 mA h g^(-1. at 0.03 A g^(-1.,which is an increase of 86 mA h g^(-1. compared to the pristine lignin-derived carbon anode(L-700-1.00),and exhibits a good rate performance(202.1.mA h g^(-1. at 1.A g^(-1.).This work provides a universal and effective guidance for tuning closed pores of hard carbons from otherprecursors.

关键词： Hard carbon Chemical activation Free radical Self-healing Closed pores Sodium ion batteries

Longitudinal changes in body weight of breastfeeding mothers in the first year after delivery and its relationship with human milk composition:a combined longitudinal and cross-sectional cohort study

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Food Science and Human Wellness 2024年第1期13卷 254-264页

作者： Huijuan Ruan Yajie Zhang Qingya Tang Xuan Zhao Xuelin Zhao yi Xiang Wei Geng yi Feng Wei Cai Department of Clinical Nutrition Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of MedicineShanghai 200092China Shanghai Key Laboratory of Pediatric Gastroenterology and Nutrition Shanghai Institute of Pediatric ResearchShanghai 200092China Department of Pediatric Surgery Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of MedicineShanghai 200092China

Objective:Postpartum weight retention(PPWR)is a common problem among women after *** main objectives of this study are to understand the changes in body weight of breastfeeding mothers during long-term follow-up and preliminarily explore the relationship between maternal body weight and human milk composition,including macronutrients,leptin,and ***:The study included a longitudinal cohort(1.2 mothers),and a cross-sectional cohort(37 mothers).The human milk,maternal weight,and dietary surveys were collected in the longitudinal cohort at different follow-up time points(1.1. days postpartum,2-4 months postpartum,5-7 months postpartum,and 1.-1. months postpartum).The maternal body weight was analyzed using the responses in the survey questionnaires.A milk analyzer based on the mid-infrared spectroscopy(MIRS)was used to determine milk composition,and nutrition analysis software evaluated dietary *** the cross-sectional cohort,participating mothers were asked to provide blood and human milk samples and pertinent information related to maternal body *** body composition was measured by bioelectrical impedance analysis(BIA),while ELISA analyzed leptin and adiponectin in milk and ***:At 5-7 months postpartum,the PPWR of breastfeeding mothers was(2.46±3.59)*** 1.-1. months postpartum,the PPWR was(0.98±4.06)*** was found to be negatively correlated with milk fat content within 1. days postpartum and positively correlated at 2-4 months *** addition,the maternal weight and body muscle mass were positively correlated with leptin and adiponectin in *** leptin was positively correlated with the mother’s body weight,body mass index(BMI),FAT percentage,and body fat mass,while plasma adiponectin did not correlate with any *** results also indicate that the PPWR did not correlate with leptin and adiponectin in plasma or ***:Breastfeeding mothers may retain considerable weight gai

关键词： Human milk Milk composition Body weight Body mass index(BMI) Weight gain Postpartum weight retention

Chain Extender-induced Hydrogen Bonding Organization Determines the Morphology and Properties of Thermoplastic Polycarbonate Polyurethane

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Chinese Journal of Polymer Science 2024年第1期42卷 87-96,I0009页

作者： yi-Lang Qin Ping Zhu Chen-Xi Ouyang Xia Dong Fuwai Hospital Chinese Academyof Medical Sciences&Peking Union Medical College/National Center for Cardiovascular DiseasesBejing 100037China CASKey Laboratoryof Engineering Plastics CAS Research/Education Centerfor Excellence in Molecular SciencesInstitute ofChemistryChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China

Thermoplastic polycarbonate polyurethanes(PCUs) are multiblock copolymers that have been applied for medical devices for long time. Aliphatic diols are common chain extenders(CE) involved in the composition of the hard segments of PCU. However, limited knowledge was discovered about how the chemical structure of CE affects the hydrogen bonding organization within PCUs and their mechanical *** investigate this problem, a group of PCUs were synthesized respectively by extending the polymer chain with 1.4-butanediol(BDO),aminoethanol(MEA), ethanediol(EO) as three kinds of chain extenders. Tiny differences in the CE chemical structure results in remarkable variations in phase separation, condensed morphologies, thermal and mechanical properties, which are characterized by Fourier transform infrared spectrometer, atomic force microscopy, small-angle X-ray scattering, differential scanning calorimetry, and tensile tests. The microstructural evolution during unilateral deformation and the different mechanism induced by the different CEs was probed and unveil by in situ wide-and small-angle X-ray diffraction. Symmetry of CE can improve the organization of the hydrogen bonding. The coherence strength of the urethane/urea group also plays a key role by comparing the two PCUs with ethanediol and aminoethanol.

关键词： Thermoplastic polycarbonate polyurethane Chain extender Hydrogen bonding Mechanical properties

Microstructure and mechanical properties of Ti/Al/Ti clad plates prepared via powder-in-tube method

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Journal of Iron and Steel Research International 2024年第3期31卷 670-687页

作者： Xian-lei Hu Qin-cheng Xie yi Yuan ying Zhi State Key Laboratory of Rolling and Automation Northeastern UniversityShenyang 110819LiaoningChina Suzhou Dongbao Haixing Metal Material Technology Co. Ltd.Suzhou 215600JiangsuChina School of Material Science and Engineering Northeastern UniversityShenyang 110819LiaoningChina

The Ti/Al/Ti clad plates exhibit a broad spectrum of potential ***,the conventional techniques of hot-pressing composite and explosive composite are intricate and environmentally hazardous.A novel method was introduced for preparing clad plates,namely,the powder-in-tube *** method involves a combination of cold rolling,annealing at a temperature of 550℃,and double *** morphology of the intermetallic compound layer was analyzed through the utilization of interface stripping test,tensile test,and microscopic *** interface morphology,interface bonding properties,tensile fracture structures,and properties of plates under the first and second rolling were compared,along with the effects of intermetallic compounds on the interface *** results indicate that the powder-in-tube method,when annealed at 550℃,can produce a composite plate featuring a complete and uniform Ti/Al *** obtained plate exhibits a peeling strength of 21.5 N/mm,tensile strength of 424 MPa,and elongation of 1..5%.Furthermore,a systematic analysis was conducted to determine the causes of performance degra-dation observed during annealing at temperatures of 600 and 650℃.

关键词： Powder-in-tube method-Ti/Al/Ti clad plate Annealing Cold rolling-Mechanical property

Trace Cobalt Doping and Defect Engineering of High Surface Area α-Ni(OH)_(2) for Electrocatalytic Urea Oxidation

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Energy & Environmental Materials 2024年第2期7卷 111-118页

作者： yi Liu Zhihui Yang Yuqin Zou Shuangyin Wang Junying He School of Metallurgy and Environment Central South UniversityChangsha 410083China State Key Laboratory of Chem/Bio-Sensing and Chemometrics College of Chemistry and Chemical EngineeringHunan UniversityChangsha 410082China

Owing to the intrinsically sluggish kinetics of urea oxidation reaction(UOR)involving a six-electron transfer process,developing efficient UOR electrocatalyst is a great challenge remained to be ***,by taking advantage of 2-Methylimidazole,of which is a kind of alkali in water and owns strong coordination ability to Co^(2+)in methanol,trace Co(1.0 mol%)addition was found to induce defect engineering onα-Ni(OH)_(2)in a dual-solvent system of water and *** characterization results revealed that the synthesized electrocatalyst(WM-Ni_(0.99)Co_(0.01.(OH)_(2))was a kind of defective nanosheet with thickness around 5-6 nm,attributing to the synergistic effect of Co doping and defect engineering,its electron structure was finely altered,and its specific surface a rea was tremendously enlarged from 68 to 1.2.3 m^(2)g^(-1..With all these merits,its overpotential to drive 1. mA cm^(-2)was reduced by 1.0 ***,the interfacial behavior of UOR was also well deciphered by operando electrochemical impedance spectroscopy.

关键词： defect engineering electrocatalysis small molecule oxidation

An analytical model of hot rolling force for a thick plate by combining globally optimal approximation yield criterion and egg-circular velocity field

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Journal of Iron and Steel Research International 2024年第3期31卷 647-659页

作者： Shun-hu Zhang yi Zhang Wen-hao Tian Yan Li Shagang School of Iron and Steel Soochow UniversitySuzhou 215021JiangsuChina

For the sake of solving the problem that it is difficult to be integrated for the Mises specific plastic power due to its nonlinearity,a new linear criterion,named the globally optimal approximation criterion,is constructed by the polygonal approximation to the Mises *** new criterion is proved to be the linear function of the principal stress componentsσ1.σ2 andσ3 and the trajectory of it on theπ-plane is a non-equiangular but equilateral dodecagon intersecting the Mises *** theoretical results of the current criterion described by the Lode stress parameters are in excellent accordance with the experimental ***,according to the trend that the metallic flow velocity between rollers aggrandizes gradually from the inlet to the outlet during the hot rolling of a thick plate,a biomimetic velocity field is proposed in which the horizontal velocity component fits the egg-circular curve *** velocity field and its simulated results agree quite ***,using the determined linear criterion,energy analysis of the constructed velocity field is utilized to obtain the interior deformation power,while the vector decomposition approach is utilized to obtain the frictional power and shear *** this basis,the overall power is obtained and the analytical solutions are generated for the rolling torque,rolling force and the coefficient of the stress state under different egg curves by minimizing the neutral ***,the parameter optimization of the characteristic parameterρwhich affects the slope of the egg-circular curve is carried out and the best egg-circular curve which can minimize the energy consumption is *** best agreement between the theoretical and observed values of rolling force and rolling torque is under this curve,and the mean relative errors of the rolling torque and rolling force are no more than 2.93%,while the maximum error is no more than 8.35%.

关键词： yield criterion Plastic deformation Rolling force Velocity field Analytical solution

Photoinduced bismuth vanadate-catalyzed C(sp^(2))-H functionalization

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Chinese Chemical Letters 2024年第3期35卷 1-2页

作者： Rong-Nan yi Wei-Min He Key Laboratory of Food&Environment&Drug Monitoring and Testing of Universities in Hunan Province Hunan Police AcademyChangsha 410138China School of Chemistry and Chemical Engineering University of South ChinaHengyang 421001China

Visible light-induced organic reactions have gained much attention in recent years due to their mild conditions and high efficiency[1.2].In this context,many efficient photocatalysts including transition metal complex... 详细信息

关键词： bismuth catalyzed gained

Vibronic coupling effect on intersystem crossing rates of TADF emitters

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Chinese Journal of Structural Chemistry 2024年第6期43卷 22-24页

作者： Xin Huang yi Zhao Wanzhen Liang State Key Laboratory of Physical Chemistry of Solid Surfaces iChEMFujian Provincial Key Lab of Theoretical and Computational ChemistryCollege of Chemistry and Chemical EngineeringXiamen UniversityXiamen361005China

To take advantage of all the singlet and triplet excitons and then achieve 1.0%internal quantum efficiency in OLED devices,the scientists have proposed the thermally activated delayed fluorescence(TADF)strategy which tries to achieve"delayed"fluorescence by converting triplet excitons to singlet excitons through a reverse intersystem crossing(ISC/RISC)process with the help of thermal activation[1..In the early days,the efficient RISC processes were facilitated by a negligible energy gap(△E_(ST))and a large spin-orbit coupling(SOC)matrix element(SOCME)between the first singlet(S_(1.)and triplet(T_(1.)excited states.

关键词： coupling system emitter