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Ramsey Numbers of Trees Versus Multiple Copies of Books

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Acta Mathematicae Applicatae Sinica 2024年第3期40卷 600-612页

作者： Xiao-bing GUO Si-nan HU yue-jian peng School of Mathematical Sciences Luoyang Normal UniversityLuoyang 471934China School of Mathematics Hunan UniversityChangsha 410082China

Given two graphs G and H,the Ramsey number R(G,H) is the minimum integer N such that any two-coloring of the edges of K_(N) in red or blue yields a red G or a blue *** v(G) be the number of vertices of G and χ(G) be the chromatic number of *** s(G) denote the chromatic surplus of G,the number of vertices in a minimum color class among all proper χ(G)-colorings of *** showed that R(G,H)≥(v(G)-1)(χ(H)-1)+s(H) if G is connected and v(G)≥s(H).A connected graph G is H-good if R(G,H)=(v(G)-1)(χ(H)-1)+s(H).Let tH denote the disjoint union of t copies of graph H,and let G∨H denote the join of G and *** a complete graph on n vertices by K_(n),and a tree on n vertices by T_(n).Denote a book with n pages by B_(n),i.e.,the join K_(2) ∨■.Erd?s,Faudree,Rousseau and Schelp proved that T_(n) is B_(m)-good if n≥*** this paper,we obtain the exact Ramsey number of T_(n) versus 2B_(2).Our result implies that T_(n) is 2B_(2)-good if n≥5.

关键词： ramsey number ramsey goodness tree book

Spatial Analysis of the Aging Population and Socio-economic Factors of China:Global and Local Perspectives

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Journal of Geodesy and Geoinformation Science 2024年第2期7卷 37-51页

作者： LU Binbin DONG Zheyi yue peng QIN Kun School of Remote Sensing and Information Engineering Wuhan UniversityWuhan 430072China

Population aging has become an inevitable trend and exerted profound influences on socio-economic development in *** this study,we utilized data from national population census and statistical yearbooks in 2010 and 2020 to explore spatio-temporal patterns of aging population and its coupling correlations with socio-economic factors from both global and local *** results from Local Indicators of Spatial Association(LISA)uncover notable spatial disparities in aging population rates,with higher rates concentrated in the eastern regions and lower rates in the western areas of the Chinese *** results from the global correlation analysis with the changes in aging population rates show significant positive correlations with government interventions and industrial structures,but negatively correlated with economic development,social consumption,and medical *** a local perspective,a Geographically Weighted(GW)correlation analysis is employed to uncover local correlations between aging trends and socio-economic *** insights gained from this technique not only underscore the complexity and diversity of economic implications stemming from population aging,but also provide invaluable guidance for crafting region-specific economic policies tailored to various stages of population aging.

关键词： spatial heterogeneity local technique GWmodelS GW correlation analysis,spatial autocorrelation

Sensing with extended gate negative capacitance ferroelectric field-effect transistors

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Chip 2024年第1期3卷 18-23页

作者： Honglei Xue yue peng Qiushi Jing Jiuren Zhou Genquan Han Wangyang Fu Key Laboratory of Advanced Materials(MOE) School of Materials Science and EngineeringTsinghua UniversityBeijing 100084China School of Microelectronics Xidian UniveristyXi’an 710071China

With major signal analytical elements situated away from the measurement environment,extended gate(EG)ion-sensitive fieldeffect transistors(ISFETs)offer prospects for whole chip circuit design and system integration of chemical *** this work,a highly sensitive and power-efficient ISFET was proposed based on a metal-ferroelectric-insulator gate stack with negative capacitance–induced super-steep subthreshold swing and ferroelectric memory *** with a remotely connected EG electrode,the architecture facilitates diverse sensing functions for future establishment of smart biochemical sensor platforms.

关键词： Extended gate Ion-sensitive field-effect transistors Negative capacitance Sub-60 mV/dec subthreshold swing Ferroelectric memory effect

Applying heteroatom co-doped carbon nanotube for manifesting high performance in the electrochemical reduction of aqueous nitrogen oxide by gold nanoparticles

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Nano Research 2024年第3期17卷 1151-1164页

作者： Jane Chung Haibo Yin Rong Wang Yunlong Wang Junyang Zhang yue peng Joung Woo Han Seongyun Ryu Junhua Li State Key Joint Laboratory of Environment Simulation and Pollution Control School of EnvironmentTsinghua UniversityBeijing 100084China EHS Research Center Samsung Electronics Co.Ltd.Gyeonggi-do 18448Republic of Korea

Electrochemical NO-to-NH_(3) under ambient conditions could be a viable alternative having advantages in terms of energy consumption and exhaust gas recycling of NO,replacing a traditional ammonia synthesis method of the Haber–Bosch *** synthesizing boron(B-)and nitrogen(N-)co-doped carbon nanotube(CNT)based gold(Au)catalysts,B-dopants elevate the conductivity of carbon nanotube by sp2 hybridization on graphene and implant B–N domains within the graphene layer,and result in facilitating the embedding amount of Au accompanied by high dispersibility with low particle *** density functional theory(DFT)calculations elucidate that the electron cloud transmitted from B-dopant to the active site of Au induces the Lewis acidic site,and the O-distal pathway occurs following a spontaneous *** of the electron-deficient B-doping area accompanied by N-defects and B–O edges retains the major valence state of Au as Au^(δ+),and suppresses hydrogen evolution reaction(HER)by repulsing the hindrance of H*.This record exhibits the highest faradaic efficiency(FE)of 94.7%,and NH_(3) yield rate of 1877.4μg·h^(-1)·mg_(cat)^(-1),which is the optimal yield over energy consumption in the field of the ambient reduction of aqueous NO.

关键词： boron heteroatom nitrogen defect gold nanoparticles valence states of gold electrochemical NO-to-NH3

Influence of reduced-port laparoscopic surgery on perioperative indicators, postoperative recovery, and serum inflammation in patients with colorectal carcinoma

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World Journal of Gastrointestinal Surgery 2024年第6期16卷 1734-1741页

作者： Hong-Biao Wu Dong-Fang Liu Ye-Lei Liu Xiao-Feng Wang yue-peng Cao Department of Colorectal Surgery The First Affiliated Hospital of Ningbo UniversityNingbo 315000Zhejiang ProvinceChina

BACKGROUND Conventional five-port laparoscopic surgery,the current standard treatment for colorectal carcinoma(CRC),has many *** To assess the influence of reduced-port laparoscopic surgery(RPLS)on perioperative indicators,postoperative recovery,and serum inflammation indexes in patients with *** The study included 115 patients with CRC admitted between December 2019 and May 2023,52 of whom underwent conventional five-port laparoscopic surgery(control group)and 63 of whom underwent RPLS(research group).Comparative analyses were performed on the following dimensions:Perioperative indicators[operation time(OT),incision length,intraoperative blood loss(IBL),and rate of conversion to laparotomy],postoperative recovery(first postoperative exhaust,bowel movement and oral food intake,and bowel sound recovery time),serum inflammation indexes[high-sensitivity C-reactive protein(hs-CRP),tumor necrosis factor-α(TNF-α),and interleukin-6(IL-6)],postoperative complications(anastomotic leakage,incisional infection,bleeding,ileus),and therapeutic *** The two groups had comparable OTs and IBL ***,the research group had a smaller incision length;lower rates of conversion to laparotomy and postoperative total complication;and shorter time of first postoperative exhaust,bowel movement,oral food intake,and bowel sound recovery;all of which were ***,hs-CRP,IL-6,and TNF-αlevels in the research group were significantly lower than the baseline and those of the control group,and the total effective rate was *** RPLS exhibited significant therapeutic efficacy in CRC,resulting in a shorter incision length and a lower conversion rate to laparotomy,while also promoting postoperative recovery,effectively inhibiting the inflammatory response,and reducing the risk of postoperative complications.

关键词： Reduced-port laparoscopic surgery Colorectal carcinoma Perioperative indicators Postoperative recovery Serum inflammation indexes

Study of inter-well interference in shale gas reservoirs by a robust production data analysis method based on deconvolution

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Petroleum Science 2024年第4期21卷 2502-2519页

作者： Wen-Chao Liu Cheng-Cheng Qiao Ping Wang Wen-Song Huang Xiang-Wen Kong Yu-Ping Sun He-Dong Sun yue-peng Jia School of Civil and Resource Engineering University of Science and Technology Beijing PetroChina Research Institute of Petroleum Exploration and Development

In order to overcome the defects that the analysis of multi-well typical curves of shale gas reservoirs is rarely applied to engineering, this study proposes a robust production data analysis method based on deconvolution, which is used for multi-well inter-well interference research. In this study, a multi-well conceptual trilinear seepage model for multi-stage fractured horizontal wells was established, and its Laplace solutions under two different outer boundary conditions were obtained. Then, an improved pressure deconvolution algorithm was used to normalize the scattered production data. Furthermore, the typical curve fitting was carried out using the production data and the seepage model solution. Finally,some reservoir parameters and fracturing parameters were interpreted, and the intensity of inter-well interference was compared. The effectiveness of the method was verified by analyzing the production dynamic data of six shale gas wells in Duvernay area. The results showed that the fitting effect of typical curves was greatly improved due to the mutual restriction between deconvolution calculation parameter debugging and seepage model parameter debugging. Besides, by using the morphological characteristics of the log-log typical curves and the time corresponding to the intersection point of the log-log typical curves of two models under different outer boundary conditions, the strength of the interference between wells on the same well platform was well judged. This work can provide a reference for the optimization of well spacing and hydraulic fracturing measures for shale gas wells.

关键词： Shale gas Inter-well interference Deconvolution Production data analysis Typical curves Multi-stage fractured horizontal well

Revealing the key role of non-solvating diluents for fast-charging and low temperature Li-ion batteries

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Journal of Energy Chemistry 2024年第7期94卷 171-180页

作者： Yuping Zhang Siyin Li Junkai Shi Jiawei Lai Ziyue Zhuang Jingwen Liu Wenming Yang Liang Ma yue-peng Cai Jijian Xu Qifeng Zheng School of Chemistry Guangzhou Key Laboratory of Materials for Energy Conversion and StorageSouth China Normal UniversityGuangzhou 510006GuangdongChina Guangzhou Foreign Language School Guangzhou 511455GuangdongChina Department of Chemistry City University of Hong KongHong Kong 999077China

Fast-charging and low temperature operation are of vital importance for the further development of lithium-ion batteries(LIBs),which is hindered by the utilization of conventional carbonate-based electrolytes due to their slow kinetics,narrow operating temperature and voltage ***,an acetonitrile(AN)-based localized high-concentration electrolyte(LHCE)is proposed to retain liquid state and high ionic conductivity at ultra-low temperatures while possessing high oxidation *** originally reveal the excellent thermal shielding effect of non-solvating diluent to prevent the aggregation of Li^(+) solvates as temperature drops,maintaining the merits of fast Li transport and facile desolvation as at room temperature,which bestows the graphite electrode with remarkable low temperature performance(264 mA h g^(-1) at-20 C).Remarkably,an extremely high capacity retention of 97%is achieved for high-voltage high-energy graphite||NCM batteries after 250 cycles at-20 C,and a high capacity of 110 mA h g^(-1)(71%of its room-temperature capacity)is retained at-30°*** study unveils the key role of the non-solvating diluents and provides instructive guidance in designing electrolytes towards fast-charging and low temperature LIBs.

关键词： Li-ion battery Fast-charging Low temperature Non-solvating diluent Shielding effect

Evolution and function of residual solvent in polymer-Li_2B_(12)H_(12) composite solid electrolyte

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Rare Metals 2024年第8期43卷 3748-3757页

作者： Xiang-Yang Ye Ke-Pan Bao Sai-Nan Luo Xin Li Tai-Qiang Chen Shui-Xin Xia Tao Yuan yue-peng Pang Shi-You Zheng School of Materials and Chemistry University of Shanghai for Science and TechnologyShanghai 200093China Department of Materials Science and Engineering National University of SingaporeSingapore 119077Singapore

Composite solid electrolytes(CSEs) containing polymer matrices and inorganic fillers hold promise for the next generation of solid-state ***,the role of residual solvents in CSEs remains *** study investigated the evolution and function of the residual solvent in a polymer-Li_2B_(12)H_(12) CSE.A partial reaction occurred between Li_2B_(12)H_(12) and solvent N,N-dimethylformamide(DMF),which produced dimethylaminomethanol(DMAM) in the *** functional theory calculations have revealed that DMA M forms stronger hydrogen bonds with polyvinylidene fluoride chains than DMF,which can have a plasticizing effect on the polymer matrix,leading to lower crystallinity and quicker segment ***,this CSE exhibited improved Li-ion conducting properties,enabling the stable cycling of Li‖LiFePO_(4) solid-state *** study provided insights into the role of residual solvents in CSEs.

关键词： Composite solid electrolyte Residual solvent Lithium borohydride Plasticizing effect

Effect of slow shot speed on externally solidified crystal,porosity and tensile property in a newly developed high-pressure die-cast Al-Si alloy

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China Foundry 2024年第1期21卷 11-19页

作者： Wen-ning Liu Wei Zhang peng-yue Wang Yi-xian Liu Xiang-yi Jiao Ao-xiang Wan Cheng-gang Wang Guo-dong Tong Shou-mei Xiong School of Materials Science and Engineering Tsinghua UniversityBeijing 100084China Key Laboratory for Advanced Materials Processing Technology Tsinghua UniversityBeijing 100084Beijing China FAW Group Co. Ltd.Changchun 130013China China FAW Foundry Co. Ltd.Changchun 130013China

The effect of slow shot speed on externally solidified crystal(ESC),porosity and tensile property in a newly developed high-pressure die-cast Al-Si alloy was investigated by optical microscopy(OM),scanning electron microscopy(SEM)and laboratory computed tomography(CT).Results showed that the newly developed AlSi9MnMoV alloy exhibited improved mechanical properties when compared to the AlSi10MnMg *** AlSi9MnMoV alloy,which was designed with trace multicomponent additions,displays a notable grain refining effect in comparison to the AlSi10MnMg *** elements Ti,Zr,V,Nb,B promote heterogeneous nucleation and reduce the grain size of primaryα-*** a lower slow shot speed,the large ESCs are easier to form and gather,developing into the dendrite net and *** an increase in slow shot speed,the size and number of ESCs and porosities significantly *** addition,the distribution of ESCs is more dispersed and the net-shrinkage *** tensile property is greatly improved by adopting a higher slow shot *** ultimate tensile strength is enhanced from 260.31 MPa to 290.31 MPa(increased by 11.52%),and the elongation is enhanced from 3.72%to 6.34%(increased by 70.52%).

关键词： hypoeutectic Al-Si alloy high pressure die casting porosity externally solidified crystal tensile property