检索结果-南通市图书馆

Chinese Chemical Letters 2024年第10期35卷 452-456页

作者： Jun-jie Fang Zheng liu Yun-Peng Xie Xing Lu State Key Laboratory of Materials Processing and Die&Mould Technology School of Materials Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074China

In core-shell silver nanoclusters,the control of core structure presents a more formidable challenge compared to that of the shell ***,we report the successful synthesis and characterization of four distinct silver thiolate nanoclusters[MS_(4)@Ag_(12)@Ag_(46)S_(24)(dppb)_(12)](M=Mo or W),each incorporating a cup-like[MS_(4)@Ag_(12)]^(2+)*** nanoclusters were meticulously prepared using(NH_(4))2Mo S4or(NH_(4))_(2)WS_(4)as both a template and a controlled source of ***,we have observed a unique configuration within these eight-electron superatomic Ag_(58) nanoclusters,where the zerovalent Ag atoms reside exclusively within the inner[MS_(4)@Ag_(12)]^(2+)*** stands in contrast to other superatomic clusters possessing an Ag(0)***,the introduction of phenyl-containing compounds during the synthesis process induced a transformation in the space group symmetry from C_(2)/c to I 4ˉ.This transformative effect was found to originate from the interplay between adjacent 1,4-bis(diphenylphosphino)butane(dppb)ligands,which facilitated enhanced emission through aggregationinduced intermolecular interactions,specifically C-H···π***,our findings contribute substantively to the understanding of the intricate relationship between nanocluster structures and their corresponding properties,shedding light on the crucial roles played by templates and diphosphine ligands in this context.

关键词： Superatom Silver nanocluster Template synthesis Photoluminescence Aggregation-induced emission

Experimental study on the effect of unloading rate on gneiss rockburst

在线全文

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and Geotechnical Engineering 2024年第6期16卷 2064-2076页

作者： Dongqiao liu jie Sun Ran Li Manchao He Binghao Cao Chongyuan Zhang Wen Meng State Key Laboratory for Tunnel Engineering China University of Mining and TechnologyBeijing100083China Key Laboratory of Active Tectonics and Geological Safety Ministry of Natural ResourcesInstitute of GeomechanicsChinese Academy of Geological SciencesBeijing100081China School of Mechanics and Civil Engineering China University of Mining and TechnologyBeijing100083China

Rockburst are often encountered in tunnel construction due to the complex geological *** study the influence of unloading rate on rockburst,gneiss rockburst experiments were conducted under three groups of unloading rates.A high-speed photography system and acoustic emission(AE)system were used to monitor the entire process of rockburst process in *** results show that the intensity of gneiss rockburst decreases with decrease of unloading rate,which is manifested as the reduction of AE energy and fragments ejection *** mechanisms are proposed to explain this effect:(i)The reduction of unloading rate changes the crack propagation mechanism in the process of *** makes the rockbursts change from the tensile failure mechanism at high unloading rate to the tension-shear mixed failure mechanism at low unloading rate,and more energy released in the form of shear crack ***,less strain energy is converted into kinetic energy of fragments ejection.(ii)Less plate cracking degree of gneiss has taken shape due to decrease of unloading rate,resulting in the destruction of rockburst incubation *** enlightenments of reducing the unloading rate for the project are also described *** rockburst magnitude is reduced from the medium magnitude at the unloading rate of 0.1 MPa/s to the slight magnitude at the unloading rate of 0.025 MPa/s,which was judged by the ejection velocity.

关键词： Rockburst Unloading rate Crack propagation Influence mechanisms

Transmit Power Minimization for IRS-Assisted NOMA-UAV Networks

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

China Communications 2024年第5期21卷 137-152页

作者： Zhao Chen Pang Xiaowei Tang jie liu Mingqian Zhao Nan Zhang Xiuyin Wang xianbin School of Information and Communication Engineering Dalian University of TechnologyDalian 116024China School of Electronic and Information Engineering South China University of TechnologyGuangzhou 510641China State Key Laboratory of Integrated Services Networks Xidian UniversityXi’an 710071China Department of Electrical and Computer Engineering Western UniversityLondonON N6A 5B9Canada

The flexibility of unmanned aerial vehicles(UAVs)allows them to be quickly deployed to support ground *** reflecting surface(IRS)can reflect the incident signal and form passive beamforming to enhance the signal in the specific *** by the promising benefits of both technologies,we consider a new scenario in this paper where a UAV uses non-orthogonal multiple access to serve multiple users with *** to their distance to the UAV,the users are divided into the close users and remote *** UAV hovers above the close users due to their higher rate requirement,while the IRS is deployed near the remote users to enhance their received *** aim at minimizing the transmit power of UAV by jointly optimizing the beamforming of UAV and the phase shift of IRS while ensuring the decoding ***,the problem is ***,we decompose it into two sub-problems,including the transmit beamforming optimization and phase shift optimization,which are transformed into second-order cone programming and semidefinite programming,*** propose an iterative algorithm to solve the two sub-problems *** results prove the effectiveness of the proposed scheme in minimizing the transmit power of UAV.

关键词： intelligent reflecting surface nonorthogonal multiple access phase shift optimization transmit beamforming optimization unmanned aerial vehicle

Performance evaluation of new epoxy resin-based composite phase change materials and their asphalt mixture

在线全文

学校读者我要写书评

暂无评论

Journal of Traffic and Transportation Engineering(English Edition) 2024年第3期11卷 507-522页

作者： Yuchao Gao Jiao Jin Shuai liu Yinfei Du Guoping Qian jie Mao Yongqiang Zhu School of Traffic and Transportation Engineering Changsha University of Science and TechnologyChangsha 410114China School of Civil Engineering Central South UniversityChangsha 410075China Guangdong Guanyue Highway and Bridge Co. Ltd.Guangzhou 511452China

In recent years,the temperature-adjusted asphalt pavement has been an extensive concern by scholars in various countries,and this pavement can reduce temperaturerelated *** this study,the shaped composite phase change materials(CPCMs)were successfully synthesized by two processes,which are vacuum impregnation and epoxy ***,the applicability of CPCMs in asphalt mixtures was evaluated by microscopic characterization,chemical compatibility,thermal properties,durability,and leakage ***,CPCMs were applied to the asphalt mixture to evaluate its temperatureadjusted characteristics and pavement ***,the performance of the temperature-adjusted asphalt mixture was analyzed by integrating all *** research shows that the prepared CPCMs have excellent thermal properties and durability,the phase transition temperature is 48.93℃,and the phase transition enthalpy is 106.5 J/g,which fully meets the requirements for use in *** temperature-adjusted asphalt mixture could alleviate the occurrence of extreme temperature,which was 4.9℃lower than the conventional *** pavement performance of the temperatureadjusted asphalt mixture can meet the specified standards for humid *** the factors,the recommended amount of CPCMs is 1.5%.The research results provide a basis for the promotion of temperature-adjusted asphalt pavement and effectively support the development of pavement engineering technology.

关键词： Pavement engineering Temperature-adjusted asphalt mixture Phase change materials Thermal performance

Sex-biased single-cell genetic landscape in mice with autism spectrum disorder

在线全文

学校读者我要写书评

暂无评论

Journal of Genetics and Genomics 2024年第3期51卷 338-351页

作者： Qian Zhang Yongjie Wang jie Tao Ruixue Xia Yijie Zhang Zhirui liu Jiwei Cheng Department of Neurology and Central Laboratory Putuo HospitalShanghai University of Traditional Chinese MedicineShanghai 200062China School of Pharmacy Hangzhou Normal UniversityHangzhouZhejiang 311121China Department of Respiratory and Critical Care Medicine Henan University Huaihe HospitalKaifengHenan 475099China

Autistic spectrum disorder(ASD)is a male-biased,heterogeneous neurodevelopmental disorder that affects approximately 1%e2%of the *** exposure to valproic acid(VPA)is a recognized risk factor for ASD,but the cellular and molecular basis of VPA-induced ASD at the single-cell resolution is ***,we aim to compare the cellular and molecular differences in the hippocampus between male and female prenatal mice with ASD at the single-cell transcriptomic *** transcriptomes of more than 45,000 cells are assigned to 12 major cell types,including neurons,glial cells,vascular cells,and immune *** type-specific genes with altered expression after prenatal VPA exposure are analyzed,and the largest number of differentially expressed genes(DEGs)are found in neurons,choroid plexus epithelial cells,and *** microglia,several pathways related to inflammation are found in both males and females,including the tumor necrosis factor(TNF),nuclear factor kappa B(NF-kB),toll-like receptor(TLR),and mitogen-activated protein kinase(MAPK)signaling pathways,which are important for the induction of autistic-like ***,we note that several X-linked genes,including Bex1,Bex3,and Gria3,were among the male-specific DEGs of *** pioneering study describes the landscape of the transcriptome in the hippocampus of autistic *** elucidation of sexual differences could provide innovative strategies for the prevention and treatment of ASD.

关键词： Autistic spectrum disorder(ASD) Sex Single cell Neurons Microglia

Dynamic response mechanism and precursor characteristics of gneiss rockburst under different initial burial depths

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Mountain Science 2024年第3期21卷 1004-1018页

作者： liu Dongqiao SUN jie MENG Wen HE Manchao ZHANG Chongyuan LI Ran CAO Binghao State Key Laboratory for Tunnel Engineering China University of Mining and TechnologyBeijing 100083China Key Laboratory of Active Tectonics and Geological Safety Ministry of Natural ResourcesInstitute of GeomechanicsChinese Academy of Geological SciencesBeijing 100081China School of Mechanics and Civil Engineering China University of Mining and TechnologyBeijing 100083China

To investigate the influence mechanism of geostress on rockburst characteristics,three groups of gneiss rockburst experiments were conducted under different initial geostress conditions.A high-speed photography system and acoustic emission(AE)monitoring system were used to monitor the entire rockburst process in real *** experimental results show that when the initial burial depth increases from 928 m to 1320 m,the proportion of large fracture scale in rockburst increases by 154.54%,and the AE energy increases by 565.63%,reflecting that the degree and severity of rockburst increase with the increase of burial *** then,two mechanisms are proposed to explain this effect,including(i)the increase of initial geostress improves the energy storage capacity of gneiss,and then,the excess energy which can be converted into kinetic energy of debris ejection increases,consequently,a more pronounced violent ejection phenomenon is observed at rockburst;(ii)the increase of initial geostress causes more sufficient plate cracks of gneiss after unloading ofσh,which provides a basis for more severe ejection of ***’s more,a precursor with clear physical meaning for rockburst is proposed under the framework of dynamic response process of crack ***,potential value in long term rockburst warning of the precursor obtained in this study is shown via the comparison of conventional precursor.

关键词： Traffic Engineering Gneiss Rockburst Crack propagation Excess energy Precursor characteristic

Artificial Intelligence Based Multi-Scenario mmWave Channel Modeling for Intelligent High-Speed Train Communications

在线全文

学校读者我要写书评

暂无评论

China Communications 2024年第3期21卷 260-272页

作者： Zhang Mengjiao liu Yu Huang jie He Ruisi Zhang Jingfan Yu Chongyang Wang Chengxiang School of Microelectronics Shandong UniversityJinan 250101China The State Key Laboratory of Rail Traffic Control and Safety Beijing Jiaotong UniversityBeijing 100044China The National Mobile Communications Research Laboratory School of Information Science and EngineeringSoutheast UniversityNanjing 210096China The Purple Mountain Laboratories Nanjing 211111China

A large amount of mobile data from growing high-speed train(HST)users makes intelligent HST communications enter the era of big *** corresponding artificial intelligence(AI)based HST channel modeling becomes a *** paper provides AI based channel characteristic prediction and scenario classification model for millimeter wave(mmWave)HST ***,the ray tracing method verified by measurement data is applied to reconstruct four representative HST *** setting the positions of transmitter(Tx),receiver(Rx),and other parameters,the multi-scenarios wireless channel big data is ***,based on the obtained channel database,radial basis function neural network(RBF-NN)and back propagation neural network(BP-NN)are trained for channel characteristic prediction and scenario ***,the channel characteristic prediction and scenario classification capabilities of the network are evaluated by calculating the root mean square error(RMSE).The results show that RBF-NN can generally achieve better performance than BP-NN,and is more applicable to prediction of HST scenarios.

关键词： artificial intelligence channel characteristic prediction HST channel millimeter wave scenario classification

MFCC based real-time speech reproduction and recognition using distributed acoustic sensing technology

在线全文

学校读者我要写书评

暂无评论

Optoelectronics Letters 2024年第4期20卷 222-227页

作者： ZHOU Ran ZHAO Shuai LUO Mingming MENG Xin MA jie liu Jianfei School of Electronic Information Engineering Hebei University of TechnologyTianjin 300401China Tianjin Key Laboratory of Electronic Materials and Devices Hebei University of TechnologyTianjin 300401China Hebei Key Laboratory of Advanced Laser Technology and Equipment Hebei University of TechnologyTianjin 300401China

The distributed acoustic sensing technology was used for real-time speech reproduction and recognition,in which the voiceprint can be extracted by the Mel frequency cepstral coefficient(MFCC)method.A classic ancient Chinese poem“You Zi Yin”,also called“A Traveler’s Song”,was analyzed both in time and frequency domains,where its real-time reproduction was achieved with a 116.91 ms time *** smaller scaled MFCC0 at 1/12 of MFCC matrix was taken as a feature vector of each line against the ambient noise,which provides a recognition method via cross-correlation among the 6 original and recovered verse *** averaged cross-correlation coefficient of the matching pairs is calculated to be 0.5806 higher than 0.1883 of the nonmatched pairs,promising an accurate and fast method for real-time speech reproduction and recognition over a passive optical fiber.

关键词： MFCC passive coefficient

Flotation separation of feldspar from quartz using sodium fluosilicate as a selective depressant

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2024年第3期43卷 1288-1300页

作者： Xin Hu xian-Ping Luo Zi-Shuai liu Yong-Bing Zhang He-Peng Zhou Zhi-Zhao Yang Xue-Kun Tang Faculty of Resource and Environmental Engineering Jiangxi University of Science and TechnologyGanzhou341000China Yichun Lithium New Energy Industry Research Institute Jiangxi University of Science and TechnologyYichun336000China

The physical and chemical properties of feldspar and quartz are highly similar,thus they cannot be easily separated *** this work,the flotation separation of feldspar from quartz using sodium fluosilicate(Na_(2)SiF_(6);SF)as a selective depressant was ***,the influence mechanism of SF on the selective flotation separation of feldspar and quartz was investigated via flotation tests,chemical analysis of flotation solution,Fourier transform infrared spectroscopy(FTIR),X-ray photoelectron spectroscopy(XPS)and contact angle *** results of the flotation tests show that feld spar and quartz without SF treatment have good *** SF treatment,feldspar still has good floatability,whereas quartz has significantly reduced *** solution chemical analysis shows that the functional group plays an important role in depressing the quartz is[SiF_(6)]^(2-).FTIR,XPS and contact angle analysis results show that[SiF_(6)]^(2-)is adsorbed only on the surface of ***,a thin hydrophilic SiOF layer is generated on the surface,which interferes with the adsorption of the collector on the surface of the *** phenomenon leads to a significant reduction in quartz's ***,SF has a good ability to separate feldspar from quartz by flotation.

关键词： Flotation separation Depressants Sodium fluorosilicate Quartz Feldspar

Yr5-virulent races of Puccinia striiformis *** possess relative parasitic fitness higher than current main predominant races and potential risk

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2024年第8期23卷 2674-2685页

作者： Gensheng Zhang Mudi Sun Xinyao Ma Wei liu Zhimin Du Zhensheng Kang jie Zhao State Key Laboratory of Crop Resistance and High-Efficiency Production College of Plant ProtectionNorthwest A&F UniversityYangling 712100China

Wheat stripe rust,caused by Puccinia striiformis ***(Pst),is one of the most destructive fungal diseases of wheat,and seriously threatens safe production of the crop *** China,new races historically appeared and rapidly developed to be predominant races and have resulted in ineffectiveness and replacement of wheat resistance cultivars as well as massive reduction in *** the present study,the relative parasitic fitness of the two newlyemerged Yr5-virulent races(TSA-6 and TSA-9)were compared with those of four currently predominant Chinese races(CYR31,CYR32,CYR33,and CYR34)based on evaluation on 10 Chinese wheat *** a result,there were significant differences in the relative parasitic fitness parameters among overall tested races based on multiple comparison(LSD)analysis(PTSA-9(0.95)>TSA-6(0.92)>CYR34(0.29)>CYR31(–1.54)>CYR33(–1.77).The results indicated that two Yr5-virulent races TSA-9 and TSA-6 possessed relative parasitic fitness higher than races CYR34,CYR31,and CYR33,but lower than race CYR32,and have potential risks in developing to be predominant ***,continual monitoring of both Yr5-virulent races,and their variants is *** use of wheat cultivars(lines)with Yr5 resistance gene singly in wheat breeding is essential for being avoided,and is suggested to combine with other effective stripe rust resistance genes.

关键词： wheat stripe rust Puccinia striiformis f.sp.tritici parasitic fitness Yr5 new race