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Rapid Phase Ambiguity Elimination Methods for DOA Estimator via Hybrid Massive MIMO Receive Array

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Chinese Journal of Electronics 2024年第1期33卷 175-184页

作者： xichao ZHAn Zhongwen SUn Feng SHU Yiwen CHEn x.n.cheng Yuanyuan WU Qi ZHAnG Yifan LI Peng ZHAnG School of Information and Communication Engineering Hainan University School of Electronic and Optical Engineering Nanjing University of Science and Technology

For a sub-connected hybrid multiple-input multiple-output(MIMO) receiver with K subarrays and n antennas, there exists a challenging problem of how to rapidly remove phase ambiguity in only single time-slot. A direction of arrival(DOA) estimator of maximizing received power(Max-RP) is proposed to find the maximum value of K-subarray output powers, where each subarray is in charge of one sector, and the center angle of the sector corresponding to the maximum output is the estimated true DOA. To make an enhancement on precision, Max-RP plus quadratic interpolation(Max-RP-QI) method is designed. In the proposed Max-RP-QI, a quadratic interpolation scheme is adopted to interpolate the three DOA values corresponding to the largest three receive powers of *** achieve the Cramer Rao lower bound, a Root-MUSIC plus Max-RP-QI scheme is developed. Simulation results show that the proposed three methods eliminate the phase ambiguity during one time-slot and also show low computational complexities. The proposed Root-MUSIC plus Max-RP-QI scheme can reach the Cramer Rao lower bound,and the proposed Max-RP and Max-RP-QI are still some performance losses 2–4 d B compared to the Cramer Rao lower bound.

关键词： Phased arrays Interpolation Wireless sensor networks Direction-of-arrival estimation Simulation Receiving antennas Massive MIMO

Optimizing 2D-metal contact in layered Tin-selenide via native oxide modulation

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nano Research 2024年第4期17卷 3014-3020页

作者： Yue Zheng Qi You Zhentian Yin Jian Tang Ke Jiang Zihao xie Henan Li cheng Han Yumeng Shi International Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology of Ministry of Education Institute of Microscale OptoelectronicsShenzhen UniversityShenzhen 518060China College of Electronics and Information Engineering Shenzhen UniversityShenzhen 518060China

The discovery of two-dimensional(2D)semiconductor has opened up new avenues for the development of short-channel field-effect transistors(FETs)with desired electrical *** them,orthorhombic tin-selenide(SnSe)has garnered increasing attention due to its potential applications in a variety of electronic,optoelectronic,and thermoelectric ***,the realization of high-performance SnSe FETs with low contact resistance(Rc)remains a ***,we systematically investigate the contact of few-layer SnSe FETs through the modulation of native oxide on SnSe by using different *** is found that chromium(Cr)-contacted devices possess the best FET performance,such as electron mobility up to 606 cm^(2)/(V·s)at 78 K,current on/off ratio exceeding 1010,and saturation current of~550μA/μm,where a negligible Schottky barrier(SB)of~30 meV and a low contact resistance of~425Ωμm are achieved.x-ray photoelectron spectroscopy(xPS)and cross-sectional electron dispersive x-ray spectroscopy(EDx)results further reveal that the improved contact arises from the Cr-induced reduction of native oxide(SnOx)to Sn,which thins the tunneling barrier for efficient electron *** findings provide a deep insight into the 2D-metal contact of SnSe and pave the way for its applications in future nanoelectronics.

关键词： few-layer SnSe field-effect transistors(FETs) Cr contact native oxide contact resistance(Rc) Schottky barrier(SB)

Approximation Algorithms for Solving the 1-Line Minimum Steiner Tree of Line Segments Problem

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Journal of the Operations Research Society of China 2024年第3期12卷 729-755页

作者： Jian-Ping Li Su-Ding Liu Jun-Ran Lichen Peng-xiang Pan Wen-cheng Wang Department of Mathematics Yunnan UniversityKunming650504YunnanChina School of Mathematics and Physics Beijing University of Chemical TechnologyBeijing650504China

We address the 1-line minimum Steiner tree of line segments(1L-MStT-LS)***,given a set S of n disjoint line segments in R^(2),we are asked to find the location of a line l and a set E_(l) of necessary line segments(i.e.,edges)such that a graph consisting of all line segments in S ∪ E_(l) plus this line l,denoted by T_(l)=(S,l,E_(l)),becomes a Steiner tree,the objective is to minimize total length of edges in E_(l) among all such Steiner ***,we are asked to find a set E_(0) of necessary edges such that a graph consisting of all line segments in S ∪ E_(0),denoted by T_(S)=(S,E_(0)),becomes a Steiner tree,the objective is to minimize total length of edges in E_(0) among all such Steiner trees,we refer to this new problem as the minimum Steiner tree of line segments(MStT-LS)*** addition,when two endpoints of each edge in Eo need to be located on two different line segments in S,respectively,we refer to that problem as the minimum spanning tree of line segments(MST-LS)*** obtain three main results:(1)Using technique of Voronoi diagram of line segments,we design an exact algorithm in time O(n log n)to solve the MST-LS problem;(2)we show that the algorithm designed in(1)is a 1.214-approximation algorithm to solve the MStT-LS problem;(3)using the combination of the algorithm designed in(1)as a subroutine for many times,a technique of finding linear facility location and a key lemma proved by techniques of computational geometry,we present a 1.214-approximation algorithm in time O(n^(3) log n)to solve the 1L-MStT-LS problem.

关键词： 1-Line minimum Steiner tree of line segments Minimum spanning tree of line segments Voronoi diagram of line segments Steiner ratio Approximation algorithms

服务业数字投入、本土市场规模与国内分工深化——兼论产业链外部风险

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经济学动态 2024年第4期 49-69页

作者：王岚程志宙天津财经大学数字经济与管理学院 300222 中央财经大学国际经济与贸易学院 100081

数字经济改变了服务业“不可贸易”和“低效率”的传统属性,为中国依托国内大市场实现服务业高质量发展、打造内需主导型价值链提供了新的契机。本文从国内生产链长视角考察数字投入对服务业国内分工深化的作用机制和效果。结果表明:数... 详细信息

数字经济改变了服务业“不可贸易”和“低效率”的传统属性,为中国依托国内大市场实现服务业高质量发展、打造内需主导型价值链提供了新的契机。本文从国内生产链长视角考察数字投入对服务业国内分工深化的作用机制和效果。结果表明:数字投入一方面能通过提升全要素生产率和资源配置效率显著增加国内生产链长,促进国内分工深化;另一方面能通过降低劳动力比较优势的重要性,推进高收入国家的国内分工深化。本土市场规模会产生逆向牵引和虹吸效应,从而强化数字投入的分工深化作用。这一结论在更靠近需求端的下游行业和门槛效应分析中得到了论证。异质性分析表明,数字投入对生产性服务业的分工深化作用更明显;数字产品投入和国外投入对国内分工深化有着显著的抑制作用;与此同时,适度降低跨境数据流动限制有利于强化分工深化效应。拓展分析表明,数字投入会通过降低生产过程外部风险提升产业链安全,本土市场规模在这过程中发挥了“蓄水池”和“压舱石”的作用。以上研究结论对于中国打造内需主导型服务业价值链,实现服务业提质增效和产业链安全稳定提供了理论和事实依据。

关键词：数字化投入生产链条长度分工深化本土市场规模外部风险

Comprehensive understanding of the thriving electrocatalytic nitrate/nitrite reduction to ammonia under ambient conditions

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Journal of Energy Chemistry 2024年第5期92卷 459-483页

作者： x.n.ing Zhao Yuzhuo Jiang Mengfan Wang Yunfei Huan Qiyang cheng Yanzheng He Tao Qian chenglin Yan Collaborative Innovation Center of Suzhou nano Science and Technology College of EnergySoochow UniversitySuzhou 215006JiangsuChina School of Chemistry and Chemical Engineering Nantong UniversityNantong 226019JiangsuChina School of Petrochemical Engineering Changzhou UniversityChangzhou 213164JiangsuChina

Ammonia(nH_(3))is a multifunctional compound that is an important feedstock for the agricultural and pharmaceutical industries and attractive energy storage *** present,nH_(3)synthesis is highly dependent on the conventional Haber–Bosch process that operates under harsh conditions,which consumes large quantities of fossil fuels and releases a large amount of carbon *** an alternative,electrosynthesis is a prospective method for producing nH_(3)under normal temperature and pressure *** electrocatalytic nitrogen reduction to ammonia has attracted considerable attentions,the low solubility of n_(2)and high n≡n cracking energy render the achievements of high nH_(3) yield rate and Faradaic efficiency *** and nitrite(nO_(x)^(-))are common n-containing *** to their high solubilities and low dissociation energy of n=O,nO_(x)^(-)−are ideal raw materials for nH_(3) ***,electrocatalytic nO_(x)^(-)−reduction to nH_(3)(enO_(x)RR)is a prospective strategy to simultaneously realise environmental protection and nH_(3) *** review offers a comprehensive understanding of the thriving enO_(x)RR under ambient *** first,the popular theory and mechanism of enO_(x)RR and a summary of the measurement system and evaluation criteria are ***,various strategies for developing nO_(x)−reduction catalysts are systematically presented and ***,the challenges and possible prospects of electrocatalytic nO_(x)^(-1) reduction are outlined to facilitate energy-saving and environmentally friendly large-scale synthesis of nH_(3) in the future.

关键词： Electrocatalytic nitrate reduction Electrocatalytic nitrite reduction Ammonia synthesis Pollutant removal Electrosynthesis

Bimetallic selenide heterostructure with directional built-in electricfield confined in n-doped carbon nanofibers for superior sodium storage with ultralong lifespan

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Journal of Energy Chemistry 2024年第4期91卷 407-416页

作者： Junying Weng Degui Zou Wenyong Yuan Pengfei Zhou Minghui Ding Jin Zhou Hailin Cong Fangyi cheng School of Materials Science and Engineering Shandong University of TechnologyZibo 255000ShandongChina School of Chemistry and Chemical Engineering Shandong University of TechnologyZibo 255000ShandongChina Key Laboratory of Advanced Energy Materials Chemistry(Ministry of Education) College of ChemistryNankai UniversityTianjin 300071China

Constructing heterostructure is considered as an effective strategy to address the sluggish electronic and ionic kinetics of anode materials for sodium ion batteries(SIBs).However,realizing the orientated growth and uniform distribution of the heterostructure is still a great ***,the regulated novel CoSe_(2)/niSe_(2)heterostructure confined in n-doped carbon nanofibers(CoSe_(2)/niSe_(2)@n-C)are prepared by using Co/ni-ZIF template,in which,the CoSe_(2)/niSe_(2)heterostructures realize uniform distribution on a micro *** from the unique heterostructure and n-doped carbon nanofibers,the CoSe_(2)/niSe_(2)@n-C deliveries superior rate capability and durable cycle lifespan with a reversible capacity of 400.5 mA h g^(-1)after 5000 cycles at 2 A g^(-1).The na-ion full battery with CoSe_(2)/niSe_(2)@n-C anode and layered oxide cathode displays a remarkable energy density of 563 W h kg^(-1)with 241.1 W kg^(-1)at 0.1 A g^(-1).The theoretical calculations disclose that the periodic and directional built-in electric-field along with the heterointerfaces of CoSe_(2)/niSe_(2)@n-C can accelerate electrochemical reaction *** in(ex)situ experimental measurements reveal the reversible conversion reaction and stable structure of CoSe_(2)/niSe_(2)@n-C during na+insertion/*** study highlights the potential ability of precisely controlled heterostructure to stimulate the electrochemical performances of advanced anode for SIBs.

关键词： CoSe_(2)/niSe_(2) heterostructure Built-in electric-field Rate capability Ultralong lifespan Sodium ion batteries

p38 MAPK inhibitor SB202190 suppresses ferroptosis in the glutamate-induced retinal excitotoxicity glaucoma model

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neural Regeneration Research 2024年第10期19卷 2299-2309页

作者： Lemeng Feng Chao Wang cheng Zhang Wulong Zhang Weiming Zhu Ye He Zhaohua xia Weitao Song national Clinical Research Center for Geriatric Diseases Xiangya Hospital of Central South UniversityChangshaHunan ProvinceChina Eye Center of xiangya Hospital Central South UniversityChangshaHunan ProvinceChina Hunan Key Laboratory of Ophthalmology ChangshaHunan ProvinceChina

Glutamate excitotoxicity has been shown to play an important role in glaucoma, and glutamate can induce ferroptosis. The p38 mitogenactivated protein kinase(MAPK) pathway inhibitor SB202190 has a potential ability to suppress ferroptosis, and its downstream targets, such as p53, have been shown to be associated with ferroptosis. However, whether ferroptosis also occurs in retinal ganglion cells in response to glutamate excitotoxicity and whether inhibition of ferroptosis reduces the loss of retinal ganglion cells induced by glutamate excitotoxicity remain unclear. This study investigated ferroptosis in a glutamate-induced glaucoma rat model and explored the effects and molecular mechanisms of SB202190 on retinal ganglion cells. A glutamate-induced excitotoxicity model in R28 cells and an n-methyl-D-aspartate-induced glaucoma model in rats were used. In vitro experiments showed that glutamate induced the accumulation of iron and lipid peroxide and morphological changes of mitochondria in R28 cells, and SB202190 inhibited these changes. Glutamate induced the levels of p-p38 MAPK/p38 MAPK and SAT1 and decreased the expression levels of ferritin light chain, SLC7A11, and GPx4. SB202190 inhibited the expression of iron death-related proteins induced by glutamate. In vivo experiments showed that SB202190 attenuated n-methyl-D-aspartate-induced damage to rat retinal ganglion cells and improved visual function. These results suggest that SB202190 can inhibit ferroptosis and protect retinal ganglion cells by regulating ferritin light chain, SAT1, and SLC7A11/Gpx4 pathways and may represent a potential retina protectant.

关键词： ferroptosis glaucoma glutamate excitotoxicity p38 MAPK retinal ganglion cell SB202190

Enhanced Crystallization of Poly(butylene adipate-co-terephthalate)by a Self-assembly nucleating Agent

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Chinese Journal of Polymer Science 2024年第5期42卷 663-674,I0010页

作者： cheng Zhou Kun Chen Zi-Heng Zhang Meng-Fan Jing Chun-Tai Liu Chang-Yu Shen Ya-Ming Wang State Key Laboratory of Structural Analysis Optimization and CAE Software for Industrial EquipmentNational Engineering Research Center for Advanced Polymer Processing TechnologyZhengzhou UniversityZhengzhou450002China

Poly(butylene adipate-co-terephthalate)(PBAT)is a promising biodegradable flexible polymer but suffers from slow crystallization rate,making it less attractive for some applications like the injection-molded products in comparison with low-density polyethylene(LDPE).This work aimed to accelerate the crystallization of PBAT by adding a self-assembly nucleating agent octamethylenedicarboxylic dibenzoylhydrazide(OMBH).PBAT/OMBH composites with various OMBH contents(0 wt%,0.5 wt%,0.7 wt%,1 wt%,2 wt%,3 wt%and 5 wt%)were prepared through *** effect of OMBH on the crystallization behavior,morphologies and mechanical properties of PBAT was *** highest nucleation efficiency value of 59.6%was achieved for PBAT with 0.7 wt%OMBH,much higher than that of 22.7%for PBAT with 0.7 wt%*** force microscopy results showed that OMBH formed fine fibers and induced the formation of transcrystalline layers of *** transform infrared spectroscopy(FTIR)combined with two-dimensional correlation spectra suggested that the intermolecular dipole-dipole n—H…O=C interactions but not hydrogen bond between OMBH and PBAT promoted the crystallization of PBAT in the initial period of *** presence of OMBH did not change the crystal form of PBAT but had positive contribution in enhancing its crystallinity and mechanical *** work is essential for preparing PBAT with high crystallization rate,enhancing its potential applications in injection-molded products.

关键词： Poly(butylene adipate-co-terephthalate) Biodegradable Self-assembly nucleating agent Crystallization

Impact of minimally invasive surgery on immune function and stress response in gastric cancer patients

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World Journal of Gastrointestinal Surgery 2024年第8期16卷 2484-2493页

作者： Rong-Hua Zhu Peng-cheng Li Jie Zhang Hua-Hua Song Department of General Surgery Chongming Hospital Affiliated to Shanghai University of Medicine and Health SciencesShanghai 202150China Department of Respiratory Medicine Chongming Hospital Affiliated to Shanghai University of Medicine and Health ScienceShanghai 202150China

BACKGROUnD Gastric cancer remains a leading cause of cancer-related mortality *** open surgery for gastric cancer is often associated with significant morbidity and prolonged *** To evaluate the effectiveness of laparoscopic minimally invasive surgery as an alternative to traditional open surgery for gastric cancer,focusing on its potential to reduce trauma,accelerate recovery,and achieve comparable oncological *** This study retrospectively analyzed 203 patients with gastric cancer who underwent surgery at the Shanghai Health Medical College Affiliated Chongming Hospital from January 2020 to December *** patients were divided into two groups:Minimally invasive surgery group(n=102),who underwent laparoscopic gastrectomy,and open surgery group(n=101),who underwent traditional open *** compared surgical indicators(surgical incision size,intraop-erative blood loss,surgical duration,and number of lymph nodes dissected),recovery parameters(time to first flatus,time to start eating,time to ambulation,and length of hospital stay),immune function(levels of IgA,IgG,and IgM),intestinal barrier function(levels of D-lactic acid and diamine oxidase),and stress response(levels of C-reactive protein,interleukin-6,and procalcitonin).RESULTS The minimally invasive surgery group demonstrated significantly better outcomes in terms of surgical indicators,including smaller incisions,less blood loss,shorter surgery time,and more lymph nodes dissected(Pn the minimally invasive surgery group,with earlier return of bowel function,earlier initiation of diet,quicker mobilization,and shorter hospital stays(Pnts in the minimally invasive surgery group had better preserved immune function,superior intestinal barrier function,and a less pronounced stress response postoperatively(PnCLUSIOn Laparoscopic minimally invasive surgery for gastric cancer not on

关键词： Gastric cancer Laparoscopic surgery Minimally invasive surgery Immune function Intestinal barrier Stress response