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Efficient and accurate worm grinding of spur face gears according to an advanced geometrical analysis and a closed-loop manufacturing process

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Journal of Central South University 2022年第1期29卷 1-13页

作者： zhou yuan-sheng TANG Zhong-wei SHI Xian-lin TANG Jin-yuan LI Zheng-min-qing State Key Laboratory of High Performance Complex Manufacturing Central South UniversityChangsha 410083China College of Mechanical and Electrical Engineering Central South UniversityChangsha 410083China National Key Laboratory of Science and Technology on Helicopter Transmission Nanjing University of Aeronautics and AstronauticsNanjing 210016China

Worm grinding has been applied to manufacture gears to pursue high accuracy and fine surface *** the worm used to grind face gears is manufactured with multi-axis computer numerical control(CNC)machining,the machining accuracy is usually improved by increasing the number of tool paths with more time ***,this work proposes a generated method to improve the efficiency by dressing the worm surface with only one path,and a closed-loop manufacturing process is applied to ensure the machining *** to an advanced geometric analysis,the worm surface is practically approximated as a swept surface generated by a planar ***,this curve is applied as the profile of a dressing wheel,which is used to dress the worm *** practical machining is carried out in a CNC machine tool,which was originally used to grind helical ***,a closed-loop manufacturing process including machining,measurement,and modification is proposed to compensate the machining *** proposed method is validated with simulations and practical experiments.

关键词： face gears worm grinding worm dressing geometrical analysis closed-loop manufacturing

Deep genome skimming reveals the hybrid origin of Pseudosasa gracilis (Poaceae: Bambusoideae)

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Plant Diversity 2024年第3期46卷 344-352页

作者： Xiang-zhou Hu Cen Guo sheng-yuan Qin De-Zhu Li Zhen-Hua Guo Germplasm Bank of Wild Species Kunming Institute of BotanyChinese Academy of SciencesKunmingYunnan 650201China University of Chinese Academy of Sciences Beijing 100049China

Pseudosasa gracilis(Poaceae:Bambusoideae)is a temperate woody bamboo species endemic to Southcentral China with a narrow *** phylogenetic studies revealed an unexpected,isolated phylogenetic position of *** we conducted phylogenomic analysis by sampling populations of *** and its sympatric species *** and Sinosasa polytricha reflecting different genomic signals,by deep genome *** molecular evidence from chloroplast genes and genome-wide SNPs,we deciphered the phylogenetic relationships of *** plastid and nuclear data indicate that *** is more closely related to Sinosasa,which is discordant with the taxonomic *** further explore this molecular-morphological conflict,we screened 411“perfect-copy”syntenic genes to reconstruct phylogenies using both the concatenation and coalescent *** observed extensive discordance between gene trees and the putative species tree.A significant hybridization event was detected based on 411 genes from the D subgenome,showing *** was a hybrid descendant between Sinosasa longiligulata and ***,with 63.56%and 36.44%inheritance probabilities of each ***,introgression events were detected in the C subgenome between *** and *** in the same distribution *** findings suggest that sympatric hybridization and introgression play a crucial role in the origin of *** providing an empirical example of bamboo of hybrid origin using comprehensive analyses based on genomic data from different inheritance systems and morphological characters,our study represents a step forward in understanding of reticulate evolution of bamboos.

关键词： Phylogenomics Hybridization Introgression Pseudosasa gracilis Pseudosasa Sinosasa

Coupling Sb_(2)WO_(6)microflowers and conductive polypyrrole for efficient potassium storage by enhanced conductivity and K^(+) diffusivity

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Journal of Energy Chemistry 2024年第2期89卷 250-258,I0007页

作者： Ruiqi Tian Hehe Zhang Zeyu yuan Yuehua Man Jianlu Sun Jianchun Bao Ming-sheng Wang Xiaosi zhou School of Chemistry and Materials Science Nanjing Normal UniversityNanjing 210023JiangsuChina State Key Lab of Physical Chemistry of Solid Surfaces College of MaterialsXiamen UniversityXiamen 361005FujianChina

Although metal oxide compounds are considered as desirable anode materials for potassium-ion batteries(PIBs)due to their high theoretical capacity,the large volume variation remains a key issue in realizing metal oxide anodes with long cycle life and excellent rate *** this study,polypyrroleencapsulated Sb_(2)WO_(6)(denoted Sb_(2)WO_(6)@PPy)microflowers are synthesized by a one-step hydrothermal method followed by in-situ polymerization and coating by *** the nanosheet-stacked Sb_(2)WO_(6)microflower structure,the improved electronic conductivity,and the architectural protection offered by the PPy coating,Sb_(2)WO_(6)@PPy exhibits boosted potassium storage properties,thereby demonstrating an outstanding rate property of 110.3 m A h g^(-1)at 5 A g^(-1)and delivering a long-period cycling stability with a reversible capacity of 197.2 m A h g^(-1)after 500 cycles at 1 A g^(-1).In addition,the conversion and alloying processes of Sb_(2)WO_(6)@PPy in PIBs with the generation of intermediates,K_(2)WO_(4)and K_(3)Sb,is determined by X-ray photoelectron spectroscopy,transmission electron microscopy,and exsitu X-ray diffraction during potassiation/*** functional theory calculations demonstrate that the robust coupling between PPy and Sb_(2)WO_(6)endues it with a much stronger total density of states and a built-in electric field,thereby increasing the electronic conductivity,and thus effectively reduces the K^(+)diffusion barrier.

关键词： Sb_(2)WO_(6) Polypyrrole coating Anode Potassium-ion battery In-situ TEM observation

Composite laminar membranes for electricity generation from water evaporation

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Nano Research 2024年第1期17卷 307-311页

作者： Xiao Wang Gang yuan Han zhou Yu Jiang Shuo Wang Jiaojiao Ma Chongyang Yang sheng Hu State Key Laboratory of Physical Chemistry of Solid Surfaces Collaborative Innovation Center of Chemistry for Energy Materials(iChEM)College of Chemistry and Chemical EngineeringXiamen UniversityXiamen 361005China Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province(IKKEM) Xiamen 361005China Pen-Tung Sah Institute of Micro-Nano Science and Technology Xiamen UniversityXiamen 361005China

Harvesting clean energy from water evaporation has been extensively investigated due to its *** achieve high efficiency,energy conversion materials should contain multiple features which are difficult to be simultaneously obtained from single-component *** we use composite laminar membranes assembled by nanosheets of graphene oxide and mica,and find a sustained power density induced by water evaporation that is two orders of magnitude larger than that from membranes made by either of the *** power output is attributed to selective proton transport driven by water evaporation through the interlayer nanochannels in the *** process relies on the synergistic effects from negatively charged and hydrophilic mica surfaces that are important for proton selectivity and water transport,and the tunable electrical conductivity of graphene oxide that provides optimized internal *** demonstrated composite membranes offer a strategy of enhancing power generation by combining the advantages from each of their components.

关键词： graphene oxide mica water evaporation electrical double layer surface charge ion selectivity

Resource Allocation for Channel Estimation in Reconfigurable Intelligent Surface-Aided Multi-Cell Networks

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Journal of Communications and Information Networks 2024年第1期9卷 64-79页

作者： Yining Xu sheng zhou Department of Electronic Engineering Beijing National Research Center for Information Science and TechnologyTsinghua UniversityBeijing 100084China

Reconfigurable intelligent surface(RIS)is a promising solution to deal with the blockage-sensitivity of millimeter wave band and reduce the high energy consumption caused by network densification. However, deploying large scale RISs may not bring expected performance gain due to significant channel estimation overhead and non-negligible reflected *** this paper,we derive the analytical expressions of the coverage probability, area spectrum efficiency(ASE)and energy efficiency (EE)of a downlink RIS-aided multi-cell *** order to optimize the network performance, we investigate the conditions for the optimal number of training symbols of each antenna-to-antenna and antenna-to-element path (referred to as the optimal unit training overhead) in channel *** study shows that:1)RIS deployment is not“the more, the better”, only when blockage objects are dense should one deploy more RISs;2) the coverage probability is maximized when the unit training overhead is designed as large as possible;3)however,the ASE-and-EE-optimal unit training overhead exists. It is a monotonically increasing function of the frame length and a monotonically decreasing function of the average signal-to-noise-ratio (in the high signal-to-noise-ratio region). Additionally,the optimal unit training overhead is smaller when communication nodes deploy particularly few or many antennas.

关键词： reconfigurable intelligent surface multi-cell network directional transmissions channel estimation resource allocation stochastic geometry

Demonstration of high-dimensional controlled quantum teleportation for the first time

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Science China(Physics,Mechanics & Astronomy) 2024年第3期67卷 163-164页

作者： Yu-Bo sheng Lan zhou College of Electronic and Optical Engineering and College of Flexible Electronics(Future Technology) Nanjing University of Posts and TelecommunicationsNanjing 210023China College of Science Nanjing University of Posts and TelecommunicationsNanjing 210023China

Controlled quantum teleportation(CQT) [1] is the tripartite version of quantum teleportation and it allows the teleportation of an unknown quantum state under the control of a third party. Compared with low-dimensional counterparts,high-dimensional CQT can exhibit larger information transmission capacity and a higher control power [2,3].

关键词： quantum dimensional high

Competition of Composition Fluctuation Modes in Weakly Segregated Salt-doped Symmetric Diblock Copolymers

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Chinese Journal of Polymer Science 2024年第9期42卷 1375-1385,I0008页

作者： yuan-Xin zhou Xian Kong South China Advanced Institute for Soft Matter Science and Technology School of Emergent Soft MatterSouth China University of TechnologyGuangzhou510640China Guangdong Provincial Key Laboratory of Functional and Intelligent Hybrid Materials and Devices South China University of TechnologyGuangzhou510640China

Salt-doped block copolymers have widespread applications in batteries,fuel cells,semiconductors,and various industries,where their properties crucially depend on phase separation ***,investigations into salt-doped diblock copolymers have predominantly focused on microphase separation,overlooking the segregation between ionic and polymeric *** study employs weak segregation theory to explore the interplay between phase separation dominated by the polymer-modulated mode and the salt-out-modulated mode,corresponding to microscopic and macroscopic phase separations,*** comparing diblock copolymers doped with salts to those doped with neutral solvents,we elucidate the significant role of charged species in modulating phase *** phase separation mode exhibits a transition between the polymer-modulated and salt-out-modulated modes at different *** systems doped with neutral solvents,this transition is stepwise,while in salt-ion-doped systems,it is *** a sufficiently large Flory-Huggins parameter between ions and polymers,the salt-out-modulated mode becomes dominant,promoting macrophase *** to the solvation effect of salt ions,salt-doped systems are more inclined to undergo microphase ***,we explore factors influencing the critical wavenumber of phase separation,including doping level and the Flory-Huggins parameters between two blocks and between ions and polymeric *** findings reveal that in a neutral solvent environment,these factors alter only the boundary between micro-and macro-phase separations,leaving the critical wavenumber unchanged in microphase separation ***,in a salt-doped environment,the critical wavenumber of microphase separation varies with these *** provides valuable insights into the pivotal role of electrostatics in the phase separation of salt-doped block copolymers.

关键词： Block copolymer Phase separation Field theory Salt-doped

Multimodal imaging diagnosis and analysis of prognostic factors in patients with adult-onset Coats disease

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International Journal of Ophthalmology(English edition) 2024年第8期17卷 1469-1476页

作者： Wei zhou Hui zhou yuan-yuan Liu Meng-Xuan Li Xiao-Han Wu Jiao Liang Jing Hao sheng-Nan Liu Chun-Jie Jin Department of Ophthalmology Tianjin Medical University General HospitalTianjin 300052China Department of Ophthalmology Shanxi Yuncheng Tongde HospitalYuncheng 044000Shanxi ProvinceChina Department of Information Tianjin Medical University General HospitalTianjin 300052China

AIM:To describe the multimodal imaging features,treatment,and outcomes of patients diagnosed with adultonset Coats ***:This retrospective study included patients first diagnosed with Coats disease at≥18 years of age between September 2017 and September *** patients received anti-vascular endothelial growth factor(VEGF)therapy(conbercept,0.5 mg)as the initial treatment,which was combined with laser photocoagulation as *** the patients underwent best corrected visual acuity(BCVA)and intraocular pressure examinations,fundus color photography,spontaneous fluorescence tests,fundus fluorescein angiography,optical coherence tomography(OCT),OCT angiography,and other *** alterations and multimodal image findings in the affected eyes following treatment were compared and the prognostic factors were ***:The study included 15 patients who were aged 24-72(57.33±12.61)y at *** hypertension was the most common associated systemic condition,occurring in 13(86.7%)*** BCVA ranged from 2.0 to 5.0(4.0±1.1),which showed improvement following treatment(4.2±1.0).Multimodal imaging revealed retinal telangiectasis in 13 patients(86.7%),patchy hemorrhage in 5 patients(33.3%),and stage 2B disease(Shield’s staging criteria)in 11 patients(73.3%).OCT revealed that the baseline central macular thickness(CMT)ranged from 129 to 964μm(473.0±230.1μm),with 13 patients(86.7%)exhibiting a baseline CMT exceeding 250μ***,8 patients(53.3%)presented with an epiretinal membrane at baseline or during ***-reflective scars were observed on OCT in five patients(33.3%)with poor visual *** deteriorated in one patient who did not receive *** vision was stable in three patients who received laser treatment,whereas improvement was observed in one of two patients who received anti-VEGF therapy *** addition,8 of 9 patients(88.9%)who received laser treatment and conbercept exhibited sta

关键词： adult-onset Coats disease multimodal imaging anti-vascular endothelial growth factor conbercept

Mechanism and control of nonuniform phase transformation of microalloyed dual-phase steel during cooling process after hot rolling

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Journal of Iron and Steel Research International 2024年第2期31卷 428-441页

作者： Wen-quan Sun sheng-yi Yong Tie-heng yuan Chao Liu San-bao zhou Rui-chun Guo Meng-xia Tang National Engineering Research Center for Advanced Rolling and Intelligent Manufacturing University of Science and Technology BeijingBeijing100083China Strip Production Plant Xichang Steel and Vanadium Corporation of Pangang GroupXichang615000SichuanChina

After cooling in the hot rolling process,the metallographic structure of microalloyed dual-phase steel is nonuniform along the rolling direction,while the thickness fluctuation of microalloyed dual-phase steel with a nonuniform metallographic structure will occur during cold *** mechanism of nonuniform phase transformation of microalloyed dual-phase steels was studied during the cooling process after hot rolling,and the nonuniform phase transformation of microalloyed dual-phase steel was regulated during the cooling process after hot rolling through process ***,the empirical equation of phase transformation temperature was measured by a dilatometer considering thermal ***,the phase field and temperature field of laminar cooling process were calculated to provide initial boundary conditions for the finite element *** that,the coupling finite element model of the temperature phase transformation of the strip steel in coiling transportation process was *** simulation results show that the different thermal contact conditions of the microalloyed dual-phase steel during coil transportation lead to uneven cooling of the coil,which leads to nonuniform transformation of the coil along the rolling *** addition,by prolonging the time interval from coiling to unloading,the phenomenon of nonuniform phase transformation of microalloyed dual-phase steel can be effectively *** simulation results are applied to industrial *** application results show that prolonging the time interval from coiling to unloading can effectively improve the nonuniform phase transformation of microalloyed dual-phase steel in the cooling process after hot rolling.

关键词： Microalloyed dual-phase steel Thickness fluctuation Cooling Heat conduction Nonuniform phase transition Finite element method