检索结果-南通市图书馆

A low-profile dual-broadband dual-circularly-polarized reflectarray for K-/Ka-band space applications

Frontiers of Information Technology & Electronic Engineering 2024年第8期25卷 1145-1161页

作者： Xuanfeng TONG zhi hao jiang Yuan LI Fan WU Lin PENG Taiwei YUE Wei HONG State Key Laboratory of Milimeter Waves School of Information Science and EngineeringSoutheast UniversityNanjing 210096China Purple Mountain Laboratories Nanjing 21lllChina State Key Laboratory of Mobile Network and Mobile Multimedia Technology ZTE CorporationShenzhen 518057China Apple Inc. One Apple Park WayCupertinoCA 95014USA

A low-profile dual-broadband dual-circularly-polarized(dual-CP)reflectarray(RA)is proposed and demonstrated,supporting independent beamforming for right-/left-handed CP waves at both K-band and *** functionality is achieved by incorporating multi-layered phase shifting elements individually operating in the K-and Ka-band,which are then interleaved in a shared aperture,resulting in a cell thickness of only about *** rotating the designed K-and Ka-band elements around their own geometrical centers,the dual-CP waves in each band can be modulated *** reduce the overall profile,planar K-/Ka-band dual-CP feeds with a broad band are designed based on the magnetoelectric dipoles and multi-branch hybrid *** planar feeds achieve bandwidths of about 32%and 26%at K-and Ka-band respectively with reflection magnitudes below-13 dB,an axial ratio smaller than 2 dB,and a gain variation of less than 1 dB.A proof-of-concept dual-band dual-CP RA integrated with the planar feeds is fabricated and characterized which is capable of generating asymmetrically distributed dual-band dual-CP *** measured peak gain values of the beams are around 24.3 and 27.3 dBic,with joint gain variation<1 dB and axial ratio<2 dB bandwidths wider than 20.6%and 14.6%at the lower and higher bands,*** demonstrated dual-broadband dual-CP RA with four degrees of freedom of beamforming could be a promising candidate for space and satellite communications.

关键词： Broadband Dual-band Dual-circularly-polarized Reflectarray Shared-aperture

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

基于5 μm厚向列相液晶的高效圆极化相控阵系统的设计、校准和实验验证

引用

Engineering 2024年第1期32卷 69-81页

作者： Xin Yu Wu Fengshuo Wan Hongyuan Feng Shichao Jin Chong Guo Yu Wei Dunge Liu Yuqian Yang Longzhu Cai zhi hao jiang Wei Hong State Key Laboratory of Millimeter Waves School ofInformation Science and Engineering Southeast UniversityNanjing 210096China State Key Laboratory of Space-Ground Integrated Information Technology Beijing Institute of Satellite Information Engineering Beijing 100095China Research Institute of Millimeter-Wave and Terahertz Technology(RIMMATT) Nanjing 211111China

This paper presents a systematic investigation and demonstration of a K-band circularly polarized liquidcrystal-based phased array(LCPA),including the design,over-the-air(OTA)in-array calibration,and experimental *** LCPA contains 16 phase-shifting radiating channels,each consisting of a circularly polarized stacked patch antenna and a liquid-crystal-based phase shifter(LCPS)based on a loaded differential line *** to its slow-wave properties,the LCPS exhibits a maximum phase-shifting range of more than 360°with a figure of merit of 78.3(°)·dB^(-1)based on a liquid crystal layer with a thickness of only 5μ***,an automatic OTA calibration based on a state ergodic method is proposed,which enables the extraction of the phase-voltage curve of every individual LCPA *** proposed LCPA is manufactured and characterized with a total profile of only 1.76 mm,experimentally demonstrating a scanned circularly polarized beam from-40°to+40°with a measured peak gain of 12.5 dBic and a scanning loss of less than 2.5 *** bandwidth of the LCPA,which satisfies the require-ments of port reflection(|S_(11)|)<-15 dB,an axial ratio(AR)<3 dB,beam squinting<3°,and a gain variation<2.2 dB,spans from 25.5 to 26.0 *** total efficiency is about 34%,which represents a new state of the *** use of the demonstrated low-profile LCPA to support circularly polarized scanning beams,along with the systematic design and calibration methodology,holds potential promise for a variety of millimeter-wave applications.

关键词： Circularly polarized Liquid crystal Liquid-crystal based phased array(LCPA) Phase shifter Over-the-air(OTA)calibration

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Predictive factors of epiretinal membrane in complicated rhegmatogenous retinal detachment tamponaded with silicone oil

引用

International Journal of Ophthalmology(English edition) 2023年第7期16卷 1110-1116页

作者： Yuan-Jie Qian Wu Xiang Yi-Meng Sun Alfira Mijit zhi-hao jiang Yan-Tao Wei State Key Laboratory of Ophthalmology Zhongshan Ophthalmic CenterSun Yat-sen UniversityGuangdong Provincial Key Laboratory of Ophthalmology and Visual ScienceGuangdong Provincial Clinical Research Center for Ocular DiseasesGuangzhou 510060Guangdong ProvinceChina

AIM:To determine the incidence and predictive factors for epiretinal membrane(ERM)formation in eyes with complicated primary rhegmatogenous retinal detachment(RRD)tamponaded with silicone oil(SO).METHODS:This retrospective case-control study included 141 consecutive patients with(51 eyes)and without(90 eyes)ERM formation after primary pars plana vitrectomy(PPV)and SO tamponade for complicated *** risk factors for ERM were assessed using logistic regression ***:The prevalence of postoperative ERM was 36.2%(51/141).Multivariate logistic regression analysis showed that the risk factors for ERM in SO-tamponaded eyes included preoperative proliferative vitreoretinopathy[PVR;odds ratio(OR),2.578;95%confidence interval(CI)1.580–4.205,P<0.001],preoperative choroidal detachment(OR,4.454;95%CI 1.369–14.498,P=0.013),and photocoagulation energy(OR,2.700;95%CI 1.047–6.962,P=0.040).The duration of the preoperative symptoms,intraocular SO tamponade time,giant retinal tear,preoperative vitreous hemorrhage,preoperative bestcorrected visual acuity,number of breaks,quadrants of RRD,axial length,and photocoagulation points were not predictive factors for ERM ***:Preoperative PVR,choroidal detachment,and photocoagulation energy are risk factors of ERM formation after complicated RRD *** ophthalmic care as well as patient education are necessary for such patients with risk factors.

关键词： epiretinal membrane rhegmatogenous retinal detachment silicone oil proliferative vitreoretinopathy

来源：

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

Learnware:small models do big

引用

Science China(Information Sciences) 2024年第1期67卷 39-50页

作者： zhi-Hua ZHOU zhi-hao TAN National Key Laboratory for Novel Software Technology Nanjing University

There are complaints about current machine learning techniques such as the requirement of a huge amount of training data and proficient training skills,the difficulty of continual learning,the risk of catastrophic forgetting,and the leaking of data privacy/*** research efforts have been focusing on one of those concerned issues separately,paying less attention to the fact that most issues are entangled in *** prevailing big model paradigm,which has achieved impressive results in natural language processing and computer vision applications,has not yet addressed those issues,whereas becoming a serious source of carbon *** article offers an overview of the learnware paradigm,which attempts to enable users not to need to build machine learning models from scratch,with the hope of reusing small models to do things even beyond their original purposes,where the key ingredient is the specification which enables a trained model to be adequately identified to reuse according to the requirement of future users who know nothing about the model in advance.

关键词： artificial intelligence machine learning learnware

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

P-symmetric Subharmonic Solutions for Nonlinear Hamiltonian Systems

引用

Acta Mathematica Sinica,English Series 2024年第6期40卷 1388-1408页

作者： Duan zhi ZHANG zhi hao Zhao School of Mathematical Sciences Nankai UniversityTianjin 300071P.R.China

In this paper,we prove that for each positive k≡1 mod m there exists a P-symmetric kmτ-periodic solution xk for asymptotically linear mτ-periodic Hamiltonian systems,which are nonautonomous and endowed with a *** the P-symmetric Hamiltonian function is semi-positive,one can prove,under a new iteration inequality of the Maslov-type P-index,that xk_(1) and xk_(2) are geometrically distinct for k_(1)/k_(2)≥(2n+1)m+1;and xk_(1),xk_(2) are geometrically distinct for k_(1)/k_(2)≥m+1 provided xk_(1) is non-degenerate.

关键词： P-symmetric subharmonic Hamiltonian systems Maslov-type index theory iteration inequality asymptotically linear

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Research on the Dynamic Compressibility of Polyurethane Microcellular Elastomer and its Application for Impact Resistance

引用

Chinese Journal of Polymer Science 2024年第8期42卷 1185-1197页

作者： zhi-Ying Zhao hao jiang Xiao-Dong Li Xu-Dong Zhang Xing Su Mei-Shuai Zou School of Materials Science and Engineering Beijing Institute of TechnologyBeijing 100081China

The packaging materials with cushioning performance are used to prevent the internal contents from being damaged by the impact and vibration of external *** polyurethane microcellular elastomers(PUMEs)can absorb energy through cell collapse and molecular chain *** this study,PUMEs with different densities were investigated by scanning electron microscopy,dynamic mechanical analysis and dynamic compression *** exhibited significant im pact resistance and the maximum peak stress attenuation ratio reached 73.33%.The protective equipment was made by PUME with the optimal density of 600 kg/m^(3),and then the acceleration sensing device installed with the same protective equipment fell from a height of 3,5 and 10 m to evaluate the energy-absorbing property and reusability of *** results showed that PUMEs equipment reduced the peak acceleration of the device by 93.84%,with a maximum deviation of 9%between actual test and simulation,and shortened the impact time of first landing by 57.39%.In addition,the equipment PUMEs equipment could effectively reduce the stress on the protected items.

关键词： Polyurethane microcellular elastomer Impact velocity Stress attenuation ratio Impact resistance

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Intermittent Theta Burst Stimulation Attenuates Cognitive Deficits and Alzheimer’s Disease-Type Pathologies via ISCA1-Mediated Mitochondrial Modulation in APP/PS1 Mice

引用

Neuroscience Bulletin 2024年第2期40卷 182-200页

作者： Yang Zhu hao Huang zhi Chen Yong Tao Ling-Yi Liao Shi-hao Gao Yan-jiang Wang Chang-Yue Gao Department of Rehabilitation Medicine Daping HospitalArmy Medical UniversityChongqing 400042China Department of Neurology and Center for Clinical Neuroscience Daping HospitalArmy Medical UniversityChongqing 400042China Department of Special Medicine Daping HospitalArmy Medical UniversityChongqing 400042China

Intermittent theta burst stimulation(iTBS),a time-saving and cost-effective repetitive transcranial magnetic stimulation regime,has been shown to improve cognition in patients with Alzheimer’s disease(AD).However,the specific mechanism underlying iTBS-induced cognitive enhancement remains *** studies suggested that mitochondrial functions are modulated by magnetic ***,we showed that iTBS upregulates the expression of iron-sulfur cluster assembly 1(ISCA1,an essential regulatory factor for mitochondrial respiration)in the brain of APP/PS1 *** vivo and in vitro studies revealed that iTBS modulates mitochondrial iron-sulfur cluster assembly to facilitate mitochondrial respiration and function,which is required for ***,iTBS rescues cognitive decline and attenuates AD-type pathologies in APP/PS1 *** present study uncovers a novel mechanism by which iTBS modulates mitochondrial respiration and function via ISCA1-mediated iron-sulfur cluster assembly to alleviate cognitive impairments and pathologies in *** provide the mechanistic target of iTBS that warrants its therapeutic potential for AD patients.

关键词： Intermittent theta burst stimulation Alzheimer’s disease Iron-sulfur cluster assembly 1 Mitochondrial dysfunction Neurodegeneration

来源：

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

Simultaneous Bulk-and Surface-initiated Living Polymerization Studied with a Heterogeneous Stochastic Reaction Model

引用

Chinese Journal of Polymer Science 2024年第3期42卷 364-372,I0008页

作者： Jia-Shu Ma zhi-Ning Huang Jia-hao Li Bang-Ping jiang Yan-Da Liao Shi-Chen Ji Xing-Can Shen State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources(Ministry of Education of China)School of Chemistry and Pharmaceutical SciencesGuangxi Normal UniversityGuilin 541004China School of Computer Science and Engineering&School of Software Guangxi Normal UniversityGuilin 541004China

To better characterize the properties of surface-initiated polymers, simultaneous bulk-and surface-initiated polymerizations are usually carried out by assuming that the properties of the surface-initiated polymers resemble those of the bulk-initiated polymers. Through a Monte Carlo simulation using a heterogeneous stochastic reaction model, it was discovered that the bulk-initiated polymers exhibit a higher molecular weight and a lower dispersity than the corresponding surface-initiated polymers, which indicates that the equivalent assumption is invalid. Furthermore, the molecular weight distributions of the two types of polymers are also different, suggesting different polymerization mechanisms. The results can be simply explained by the heterogeneous distributions of reactants in the system. This study is helpful to better understand surface-initiated polymerization.

关键词： Surface-initiated polymerization Polymer brush Stochastic reaction model Heterogeneous polymerization Simultaneous polymerization

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Development and validation of a machine learning-based early prediction model for massive intraoperative bleeding in patients with primary hepatic malignancies

引用

World Journal of Gastrointestinal Oncology 2024年第1期16卷 90-101页

作者： Jin Li Yu-Ming Jia zhi-Lei Zhang Cheng-Yu Liu Zhan-Wu jiang zhi-Wei hao Li Peng Department of Hepatological Surgery The Fourth Hospital of Hebei Medical UniversityShijiazhuang 050011Hebei ProvinceChina Department of General Surgery II Baoding First Central HospitalBaoding 071000Hebei ProvinceChina

BACKGROUND Surgical resection remains the primary treatment for hepatic malignancies,and intraoperative bleeding is associated with a significantly increased risk of ***,accurate prediction of intraoperative bleeding risk in patients with hepatic malignancies is essential to preventing bleeding in advance and providing safer and more effective *** To develop a predictive model for intraoperative bleeding in primary hepatic malignancy patients for improving surgical planning and *** The retrospective analysis enrolled patients diagnosed with primary hepatic malignancies who underwent surgery at the Hepatobiliary Surgery Department of the Fourth Hospital of Hebei Medical University between 2010 and *** regression analysis was performed to identify potential risk factors for intraoperative bleeding.A prediction model was developed using Python programming language,and its accuracy was evaluated using receiver operating characteristic(ROC)curve *** Among 406 primary liver cancer patients,16.0%(65/406)suffered massive intraoperative *** regression analysis identified four variables as associated with intraoperative bleeding in these patients:ascites[odds ratio(OR):22.839;P<0.05],history of alcohol consumption(OR:2.950;P<0.015),TNM staging(OR:2.441;P<0.001),and albumin-bilirubin score(OR:2.361;P<0.001).These variables were used to construct the prediction *** 406 patients were randomly assigned to a training set(70%)and a prediction set(30%).The area under the ROC curve values for the model’s ability to predict intraoperative bleeding were 0.844 in the training set and 0.80 in the prediction *** The developed and validated model predicts significant intraoperative blood loss in primary hepatic malignancies using four preoperative clinical factors by considering four preoperative clinical factors:ascites,history of alcohol consumption,TNM staging,and albumin-bilirubin ***

关键词： Primary liver cancer Intraoperative bleeding Machine learning Model

来源：

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

Novel Sum-of-Sinusoids Simulation Channel Modeling for 6G Multiple-Input Multiple-Output Vehicle-to-Everything Communications

引用

China Communications 2024年第1期21卷 242-259页

作者： hao jiang Hongming Zhang Ting Liu College of Artificial Intelligence Nanjing University of Information Science and Technology210044China National Mobile Communications Research Laboratory Southeast UniversityNanjing 210096China School of Information and Communication Engineering Beijing University of Posts and TelecommunicationsChina

In this paper,a statistical cluster-based simulation channel model with a finite number of sinusoids is proposed for depicting the multiple-input multiple-output(MIMO)communications in vehicleto-everything(V2X)*** the proposed sum-of-sinusoids(SoS)channel model,the waves that emerge from the transmitter undergo line-of-sight(LoS)and non-line-of-sight(NLoS)propagation to the receiver,which makes the model suitable for describing numerous V2X wireless communication scenarios for sixth-generation(6G).We derive expressions for the real and imaginary parts of the complex channel impulse response(CIR),which characterize the physical propagation characteristics of V2X wireless *** statistical properties of the real and imaginary parts of the complex CIRs,i.e.,autocorrelation functions(ACFs),Doppler power spectral densities(PSDs),cross-correlation functions(CCFs),and variances of ACFs and CCFs,are derived and *** results are generated and match those predicted by the underlying theory,demonstrating the accuracy of our derivation and *** proposed framework and underlying theory arise as an efficient tool to investigate the statistical properties of 6G MIMO V2X communication systems.

关键词： complex CIRs LoS and NLoS propagation components MIMO V2X communication environments SoS simulation channel model statistical properties

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：