检索结果-南通市图书馆

Lightweight foam-like nitrogen-doped carbon nanotube complex achieving highly efficient electromagnetic wave absorption

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2024年第1期168卷 114-123页

作者： Zongcheng Li Jin Liang Zhiheng Wei Xin Cao Jiahui Shan Chunwei Li Xiaoyi Chen Dong Zhou Ruizhe Xing Chunjia Luo Jie Kong MOE Key Lab of Materials Physics and Chemistry in Extraordinary Conditions Shaanxi Key Laboratory of Macromolecular Science and TechnologySchool of Chemistry and Chemical EngineeringNorthwestern Polytechnical UniversityXi’an 710072China Key laboratory of Flexible Electronics of Zhejiang Province Ningbo Institute of Northwestern Polytechnical UniversityNingbo 315103China Polymer Materials and Engineering Department School of Materials Science and EngineeringChang’an UniversityXi’an 710064China

With the increased electromagnetic wave(EMW)threat to military and human health,the develop-ment of EMW-absorbing materials is ***-organic framework derivatives containing magnetic nanoparticles and a carbon matrix are potential candidates for designing efficient EMW-absorbing ***,a zeolitic imidazolate framework-67(ZIF-67)-embedded three-dimensional melamine foam is pyrolyzed to afford carbon foam-based nitrogen-doped carbon nanotube composites,named 3D foam-like CoO/Co/*** CoO/Co particles are confined in the dielectric carbon nanotube *** carbon nanotubes provide considerable conductive loss,while CoO/Co magnetic particles are con-ducive to providing magnetic loss and adjusting impedance ***,the numerous defect structures introduced by heteroatomic doping(nitrogen)cause dipole polarization and simultaneously adjust impedance ***,the unique porous nanotube structure promotes multiple re-flections and scattering of EMWs,further optimizing impedance ***/Co/N-CNTs composites exhibit a minimum reflection loss of−52.3 dB at a matching thickness of 2.0 mm,while the correspond-ing effective absorption bandwidth is 5.28 GHz at a matching thickness of 2.2 *** study reports a novel approach to fabricating a lightweight high-performance EMW-absorbing material.

关键词： Lightweight porous carbon materials Carbon nanotubes CoO/Co magnetic particles Electromagnetic synergistic effect Impedance matching

Ultra reliability and massive connectivity provision in integrated internet of military things(IoMT)based on tactical datalink

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2024年第3期33卷 386-398页

作者： Li Bing Yating Gu Lanke Hu Li Bowen Yang Lihua Jue Wang Yue Yin northwestern polytechnical university Xi'an 710072China China Academy of Information and Communications Technology Beijing 100191China China Intelligent and Connected Vehicles(Beijing)research institute Co. LtdBeijing 100176China The 20th research institute of China Electronic Technology Group Corporation Xi’an 710068China Xidian university Xi'an 710071China

One of the major challenges arising in internet of military things(IoMT)is accommodating massive connectivity while providing guaranteed quality of service(QoS)in terms of ultra-high *** this regard,this paper presents a class of code-domain nonorthogonal multiple accesses(NOMAs)for uplink ultra reliable networking of massive IoMT based on tactical datalink such as Link-16 and joint tactical information distribution system(JTIDS).In the considered scenario,a satellite equipped with Nr antennas servers K devices including vehicles,drones,ships,sensors,handset radios,*** coded modulation,a special form of multiple input multiple output(MIMO)-NOMA is *** discussion starts with evaluating the output signal to interference-plus-noise(SINR)of receiver filter,leading to the unveiling of a closed-form expression for overloading systems as the number of users is significantly larger than the number of devices admitted such that massive connectivity is *** expression allows for the development of simple yet successful interference suppression based on power allocation and phase shaping techniques that maximizes the sum rate since it is equivalent to fixed-point programming as can be *** proposed design is exemplified by nonlinear modulation schemes such as minimum shift keying(MSK)and Gaussian MSK(GMSK),two pivotal modulation formats in IoMT standards such as Link-16 and *** results show that near capacity performance is ***,the performance is obtained using simple forward error corrections(FECs)of higher coding rate than existing schemes do,while the transmit power is reduced by 6 *** proposed design finds wide applications not only in IoMT but also in deep space communications,where ultra reliability and massive connectivity is a keen concern.

关键词： Satellite network Deep space communications Internet of military things Non-orthogonal multiple access MIMO Link-16 JITDS

MACF1 deficiency suppresses tooth mineralization through IGF1 mediated crosstalk between odontoblasts and ameloblasts

在线全文

学校读者我要写书评

暂无评论

Genes & Diseases 2024年第5期11卷 9-12页

作者： Wuxia Qiu Xiao Lin Shaoqing Yang Zhihao Chen Kewen Zhang Chaofei Yang Yu Li Zhiping Miao Xiaoni Deng Xiaohong Duan Airong Qian Lab for Bone Metabolism Xi’an Key Laboratory of Special Medicine and Health EngineeringKey Lab for Space Biosciences and BiotechnologyResearch Center for Special Medicine and Health Systems EngineeringNPU-UAB Joint Laboratory for Bone MetabolismSchool of Life SciencesNorthwestern Polytechnical UniversityXi’anShaanxi 710072China State Key Laboratory of Military Stomatology National Clinical Research Center for Oral DiseasesDepartment of Oral BiologyClinic of Oral Rare and Genetic DiseasesSchool of StomatologyThe Fourth Military Medical UniversityXi’anShaanxi 710032China School of Chemical Engineering Sichuan University of Science&EngineeringZigongSichuan 643000China research&Development institute of northwestern polytechnical university in shenzhen ShenzhenGuangdong 518063China Puyang institute of Technology Henan UniversityPuyangHenan 457000China

Tooth mineralization is a ubiquitous and tightly regulated process involving complicated interactions between dental epithelium and *** molecules in tooth mineralization remain poorly *** actin cross-linking factor 1(MACF1)is a spectraplakin protein that plays pivotal roles in the brain,muscle,lung,and bone developmental process.^(1-3) To study the specific functions of MACF1 in bone formation,we established Macf1 conditional knockout mice using the Cre-LoxP system driven by Osxterix promoter(Osx-Cre;Macf1^(f/f)).^(2) Not surprisingly,Osx-Cre;Macf1^(f/f) mice displayed the phenotypes of delayed ossification and decreased bone ***,the OsxCre;Macf1^(f/f) mice unexpectedly showed a white and opaque appearance of incisors,contrary to the normal yellowbrown and transparent *** Osxterix is expressed in dental mesenchyme during tooth development,the abnormal tooth appearance might imply a new function of MACF1 in odontoblasts,or even ***,the present study aimed to investigate the role of MACF1 during tooth development.

关键词： mineralization linking transparent

CD147 facilitates cisplatin resistance in ovarian cancer through FOXM1 degradation inhibition

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Genes & Diseases 2024年第5期11卷 122-125页

作者： Miao Wang Lin Chen Yu Wang Tian Fan Chunyu Zhu Zhixian Li Lei Mou Hong Yang Airong Qian Yu Li School of Life Sciences Northwestern Polytechnical UniversityXi’anShaanxi 710072China Xi’an Key Laboratory of Stem Cell and Regenerative Medicine Institute of Medical ResearchNorthwestern Polytechnical UniversityXi’anShaanxi 710072China Department of Oncology Air Force Medical CenterPLABeijing 100142China Department of Obstetrics and Gynecology The First Affiliated Hospital of Air Force Medical UniversityXi’anShaanxi 710032China

Currently,the major therapy for patients with ovarian cancer includes post-cytoreductive surgery followed by chemotherapy of carboplatin or cisplatin plus *** rise of drug resistance is a substantial factor in cancer recurrence and mortality among ovarian cancer patients receiving cisplatin ***147 is widely expressed in a variety of cancer tissues1 and recognized as a drug target for its antibody drug Licartin which has been approved by China’s National Medicines and Pharmaceutical Administration.2 Even though many studies reported that CD147 is involved in the cisplatin resistance of varieties of cancers,3 its mechanism remains *** this investigation,we uncovered a distinctive mechanism by which CD147 regulates cisplatin resistance through the proteasomal degradation of the transcription factor FOXM1,which is associated with DNA damage repair,in ovarian cancer *** results suggest that targeting CD147 may have therapeutic implications for increasing cisplatin efficiency in the management of ovarian cancer.

关键词： FOXM1 cisplatin CD147

An Assembly of Pyrano[3,2-b]indol-2-ones via NHC-Catalyzed[3+3]Annulation of Indolin-3-ones with Ynals

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2024年第13期42卷 1487-1492页

作者： Xia Wang Shulei Zhang Shao-Jie Wang Hao An Xiaolan Xin Haonan Lin Zhifeng Tu Shenci Lu Frontiers Science Center for Flexible Electronics(FSCFE) Shaanxi Institute of Flexible Electronics(SIFE)&Shaanxi Instituteof Biomedical Materials and Engineering(SiBME)Northwestern Polytechnical University(NPU)127 West Youyi RoadXi'anShaanxi 710072China School of Chemistry and Chemical Engineering Northwestern Polytechnical University(NPU)127 West Youyi RoadXi'anShaanxi 710072China

We report herein an unprecedented N-heterocyclic carbene-catalyzed formal[3+3]annulation of ynals with N-Ts indolin-3-ones under the oxidation condition affording the functionalized pyrano[3,2-b]*** alkynyl acylazoliums via the combination of a carbene with ynals in the presence of oxidate proved to be the important intermediates for the success of this *** method features a broad substrate scope and mild conditions,including axially chiral skeletons with suitable substitutions.

关键词： N-Heterocyclic carbene Annulation Organocatalysis Atropisomerism Carbazole Aldehydes Heterocycles Asymmetric catalysis

Multi-scale design of silicon/carbon composite anode materials for lithium-ion batteries:A review

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 Energy Chemistry 2024年第10期97卷 30-45页

作者： Liu Yang Shuaining Li Yuming Zhang Hongbo Feng Jiangpeng Li Xinyu Zhang Huai Guan Long Kong Zhaohui Chen State Key Laboratory of Heavy Oil Processing China University of Petroleum-Beijing State Key Laboratory of Mesoscience and Engineering Institute of Process Engineering Chinese Academy of Sciences institute of Flexible Electronics (IFE) Northwestern Polytechnical University

Silicon/carbon composites,which integrate the high lithium storage performance of silicon with the exceptional mechanical strength and conductivity of carbon,will replace the traditional graphite electrodes for high-energy lithium-ion *** strategies have been designed to synthesize silicon/carbon composites for tackling the issues of anode pulverization and poor stability in the anodes,thereby improving the lithium storage *** effect of the regulation method at each scale on the final negative electrode performance remains ***,it has not been fully clarified how the regulation methods at each scale influence the final anode *** review will categorize the materials structure into three scales:molecular scale,nanoscale,and ***,the review will examine modification methods at the molecular scale,focusing on the interfacial bonding force between silicon and ***,it will summarize various nanostructures and special shapes in the nanoscale to explore the construction of silicon/carbon ***,the review will provide an analysis of microscale control approaches,focusing on the formation of composite particle with micron size and the utilization of *** review provides a comprehensive overview of the multi-scale design of silicon/carbon composite anode materials and their optimization strategies to enhance the performance of lithium-ion batteries.

关键词： Lithium-ion batteries Microscale Molecular scale Nanoscale Silicon/carbon composites

Universal method for designing periodic orbits by homotopy classes in the elliptic restricted three-body problem

在线全文

学校读者我要写书评

暂无评论

Astrodynamics 2024年第1期8卷 175-188页

作者： Yue Zheng Min Zhao School of Electronic Engineering Xi’an Aeronautical InstituteXi’an710077China School of Aircraft Engineering Xi’an Aeronautical InstituteXi’an710077China School of Astronautics Northwestern Polytechnical UniversityXi’an710072China

The current methods for designing periodic orbits in the elliptic restricted three-body problem(ERTBP)have the disadvantages of targeting limited orbits and ergodic searches and considering only symmetric orbits.A universal method for designing periodic orbits is proposed in this ***,the homotopy classes of orbits are structured based on their topological ***,a dynamic model based on homotopy classes,ranging from the circular restricted three-body problem(CRTBP)to the ERTBP,can be built using the homotopy ***,a multi-and a single-period orbit were selected based on the resonance ***,the corresponding orbit in the ERTBP was computed by modifying the initial condition of the orbit in the *** method,without an ergodic search,can extend to any orbit,including an asymmetric orbit in the CRTBP,to the ERTBP model,and the two orbits are of the same homotopy *** of the Earth–Moon ERTBP are presented to verify the efficiency of this method.

关键词： periodic orbit elliptic restricted three-body problem(ERTBP) topology homotopy circular restricted three-body problem(CRTBP)

Radiated noise measurement method of underwater low noise target by a vertical nested array

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Acoustics 2024年第1期43卷 98-112页

作者： LI Xuegang JIANG Guoqing SUN Guocang HUA Runan ZHU Jie Wuhan Second Ship Design and research institute Wuhan 430205 School of Marine Science and Technology Northwestern Polytechnical UniversityXi'an 710072

A radiated noise measurement method of underwater acoustic targets with relatively low power by a vertical nested array is studied. Firstly, the array gain requirements for different frequency bands are obtained through comparative analysis of the background noise level and the radiated noise level of the target. Secondly, an ultra wideband constant-beamwidth beamforming method with high robustness is established for the waveguide environment based on convex optimization. The radiated noise measurement and the following spatial array signal processing procedure is formulated. Finally, a vertical nested array measurement system is developed, and the radiated noise measurement method is verified using lake test data. Experimental results show that the radiated noise measurement method has large working bandwidth, high robustness and low measurement uncertainty of about 2 dB.

关键词： underwater method bands

多芯绞扭Nb_(3)Sn超导股线弹塑性损伤和临界电流不可逆退化的细观力学建模

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Sinica 2024年第4期40卷 49-60页

作者：景泽张雨 institute of Extreme Mechanics and School of Aeronautics Northwestern Polytechnical UniversityXi’an710072China

Nb_(3)Sn被广泛接受是实现高场超导磁体的关键材料.然而,Nb_(3)Sn是脆性材料且其超导性能具有应变敏感性.在强磁场应用中,Nb_(3)Sn股线会受到显著的弹塑性应变甚至损伤,导致其载流能力下降.本文基于细观力学方法建立了三维平均场均匀化... 详细信息

Nb_(3)Sn被广泛接受是实现高场超导磁体的关键材料.然而,Nb_(3)Sn是脆性材料且其超导性能具有应变敏感性.在强磁场应用中,Nb_(3)Sn股线会受到显著的弹塑性应变甚至损伤,导致其载流能力下降.本文基于细观力学方法建立了三维平均场均匀化模型,研究多芯绞扭Nb_(3)Sn超导股线的弹塑性损伤行为和临界电流的不可逆退化.计算股线在单调和循环载荷作用下的等效应力-应变曲线以及Nb_(3)Sn内部的应变分布.采用辅以损伤引起退化的应变不变量标度律来表征临界电流的不可逆退化.研究发现,绞扭对股线弹塑性损伤行为和应变导致的临界电流退化起着重要作用.随着绞扭节距的增大,复合股线的刚度增大,应变极限(超过该极限时芯丝开始损伤)急剧减小.累积残余应变和芯丝的损伤共同导致超导股线临界电流的不可逆退化.实验观察到的“断崖式不可逆退化”是由于Nb_(3)Sn芯丝的损伤造成的.从力学的角度,短绞节距是缓解应变引起超导股线临界电流不可逆退化的良好选择.

关键词：临界电流弹塑性损伤 Nb_(3)Sn 弹塑性应变细观力学超导性能股线循环载荷