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Simulation of RFI Cancellation Using Subspace Projection Algorithm for PAF Receiver

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Research in Astronomy and Astrophysics 2024年第1期24卷 237-244页

作者： Peng Wu Jian Li Mao-zheng chen Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China University of Chinese Academy of Sciences Beijing 100049China Xinjiang Key Laboratory of Microwave Technology Urumqi 830011China

The simulation of radio frequency interference(RFI) cancellation by applying a spatial filtering technique for phased array feed(PAF) is presented. In order to better reflect the characteristics of PAF, a new signal model is to add the coupling coefficient among elements of PAF to the conventional array signal model. Then the subspace projection(SP) algorithm is used to cancel RFI from the correlation matrix of the signal, and finally, the 2D power image is drawn. The power variation of signal-of-interest direction and RFI direction before and after using the SP algorithm is analyzed. The new signal model and simulation strategy can be used to test and verify the beamformer.

关键词： methods:analytical techniques:radar astronomy telescopes

Observer-Based Adaptive Robust Precision Motion Control of a Multi-Joint Hydraulic Manipulator

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IEEE/CAA Journal of Automatica Sinica 2024年第5期11卷 1213-1226页

作者： zheng chen Shizhao Zhou Chong Shen Litong Lyu Junhui Zhang Bin Yao State Key Laboratory of Fluid Power and Mechatronic Systems Zhejiang UniversityHangzhou 310027 Ocean College Zhejiang UniversityZhoushan 316021China School of Mechanical Engineering Shijiazhuang Tiedao UniversityShijiazhuang 050000 State Key Laboratory of Fluid Power and Mechatronic Systems Zhejiang UniversityHangzhou 310027China School of Mechanical Engineering Purdue UniversityWest LafayetteIN 47907 USA

Hydraulic manipulators are usually applied in heavy-load and harsh operation tasks.However,when faced with a complex operation,the traditional proportional-integral-derivative(PID)control may not meet requirements for high control performance.Model-based full-state-feedback control is an effective alternative,but the states of a hydraulic manipulator are not always available and reliable in practical applications,particularly the joint angular velocity measurement.Considering that it is not suitable to obtain the velocity signal directly from differentiating of position measurement,the low-pass filtering is commonly used,but it will definitely restrict the closed-loop bandwidth of the whole system.To avoid this problem and realize better control performance,this paper proposes a novel observerbased adaptive robust controller(obARC)for a multi-joint hydraulic manipulator subjected to both parametric uncertainties and the lack of accurate velocity measurement.Specifically,a nonlinear adaptive observer is first designed to handle the lack of velocity measurement with the consideration of parametric uncertainties.Then,the adaptive robust control is developed to compensate for the dynamic uncertainties,and the close-loop system robust stability is theoretically proved under the observation and control errors.Finally,comparative experiments are carried out to show that the designed controller can achieve a performance improvement over the traditional methods,specifically yielding better control accuracy owing to the closed-loop bandwidth breakthrough,which is limited by low-pass filtering in fullstate-feedback control.

关键词： handle Observer filtering

Hepatocyte-specific deletion of Mettl3 promotes hepatocellular carcinoma in mice

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Genes & Diseases 2024年第1期11卷 57-59页

作者： Chunhong Liu Xinzhi Li Zhicheng Yao Xueying Li zheng chen HIT Center for Life Sciences School of Life Science and TechnologyHarbin Institute of TechnologyHarbinHeilongjiang150001China Department of General Surgery The Third Affiliated Hospital of Sun Yat-sen UniversityGuangzhouGuangdong 510530China

Hepatocellular carcinoma(HcC)is a key cause of morbidity and mortality,which is a global health problem.Elucidating the molecular and cellular mechanisms of HcC progression is helpful to find either early markers for ... 详细信息

关键词： diagnosis mortality carcinoma

MoP nanoparticles encapsulated in N-doped carbon nanotubes as sulfur host for advanced lithium-sulfur batteries

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Nano Research 2024年第4期17卷 2736-2745页

作者： Guozhi Wu Shanqing Li zheng chen Ajiao Sun Jie Yang Sang Woo Joo Jiarui Huang Key Laboratory of Functional Molecular Solids of the Ministry of Education Anhui Laboratory of Molecule-Based MaterialsCollege of Chemistry and Materials ScienceAnhui Normal UniversityWuhu 241002China Anhui Engineering Research Center of Highly Reactive Micro-Nano Powders School of Materials and Environmental engineeringChizhou UniversityChizhou 247000China School of Mechanical Engineering Yeungnam UniversityGyeongsanGyeongbuk 38541Republic of Korea

The low electrical conductivity of sulfur,strong volume expansion,shuttle effect,and sluggish redox reactions in Li-S batteries limit their practical application.MoP nanoparticles encapsulated in nitrogen-doped carbon nanotubes(MoP/NC NTs)were synthesized using MoO_(3) nanorods as templates via a polypyrrole coating,heat-carbonization,MoO_(3) partial reduction,ammonia washing,and phosphorization.The MoP/NC NTs had a hollow nanostructure with a high specific surface area,which can alleviate the volume expansion of the cathode and the shuttle effect of polysulfides.The encapsulated MoP nanoparticles can anchor the polysulfides and enhance the redox reaction kinetics.Thus,the MoP/NC NTs combined with sulfur(MoP/S/NC NTs)exhibited 440.8 mAh·g^(-1) over 500 cycles at 1.0 A·g^(-1) with a decay rate of 0.06%per cycle.The density functional theory calculations and X-ray photoelectron spectroscopy results confirmed that MoP/NC NTs could anchor polysulfides and alleviate the shuttle effect by chemical interactions.This study supplies a novel route to prepare nanoparticle-embedded in N-doped carbon nanotubes for advanced Li-S battery.

关键词： MoP N-doped carbon nanotube lithium-sulfur battery cathode

An alternative approach to improve the compatibility of PCE in cement paste blend with coal gangue powder

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Waste Disposal and Sustainable Energy 2024年第1期6卷 139-150页

作者： Zonglin Xie Yuxuan Li Dahui Sun Yi Tian Jinyuan Hu Qiang Yuan zheng chen School of Civil Engineering Central South UniversityChangshaChina China Railway NO.9 Group CO. LTDShenyangChina National Engineering Research Center for High-Speed Railway Construction Technology ChangshaChina Guangxi Key Laboratory of Disaster Prevention and Engineering Safety Guangxi UniversityNanningChina

Coal gangue(CG)is an environmental waste that faces an urgent demand for disposal in China.The utilization of CG in construction materials has broad application prospects and gained increasing interest.However,the poor compatibility of polycarboxylate superplasticizer(PCE)with CG powder hinders its efficiency in a wide range of applications.Here,this paper attempts to improve the compatibility of PCE with CG powder in cement paste based on the regulation of aggregation and the adsorption behavior of PCE.Dynamic light scattering(DLS)and fluorescence spectroscopy tests were carried out to understand the improved mechanism.The results indicated that the addition of CG powder increases the ionic strengths of the cement liquid phase,which makes PCE tend to aggregate at a lower concentration compared with no CG powder introduction.Adding(CH_(3)COO)_(2)Cu is beneficial for enhancing the workability of cement paste by reducing PCE aggregation while maintaining the compressive strength of cement specimens.Therefore,(CH_(3)COO)_(2)Cu extra addition can be regarded as an effective and sustainable way to improve the workability of cement paste with CG powder.

关键词： Coal gangue powder Polycarboxylate superplasticizer Compatibility Aggregation

KLF6 facilitates differentiation of odontoblasts through modulating the expression of P21 in vitro

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International Journal of Oral Science 2022年第2期14卷 220-230页

作者： Zhuo chen Wenzhi Wu chen zheng Yanhua Lan Huizhi Xie Zhijian Xie Stomatology Hospital School of StomatologyZhejiang University School of MedicineClinical Research Center for Oral Diseases of Zhejiang ProvinceKey Laboratory of Oral Biomedical Research of Zhejiang ProvinceCancer Center of Zhejiang UniversityHangzhouChina

Multiple signaling pathways are involved in the regulation of cell proliferation and differentiation in odontogenesis and dental tissue renewal,but the details of these mechanisms remain unknown.Here,we investigated the expression patterns of a transcription factor,Krüppel-like factor 6(KLF6),during the development of murine tooth germ and its function in odontoblastic differentiation.KLF6 was almost ubiquitously expressed in odontoblasts at various stages,and it was co-expressed with P21(to varying degrees)in mouse dental germ.To determine the function of Klf6,overexpression and knockdown experiments were performed in a mouse dental papilla cell line(iMDP-3).Klf6 functioned as a promoter of odontoblastic differentiation and inhibited the proliferation and cell cycle progression of i MDP-3 through p21 upregulation.Dual-luciferase reporter assay and chromatin immunoprecipitation showed that Klf6 directly activates p21 transcription.Additionally,the in vivo study showed that KLF6 and P21were also co-expressed in odontoblasts around the reparative dentin.In conclusion,Klf6 regulates the transcriptional activity of p21,thus promoting the cell proliferation to odontoblastic differentiation transition in vitro.This study provides a theoretical basis for odontoblast differentiation and the formation of reparative dentine regeneration.

关键词： KLF6 inhibited details

Development of a Front End Array for Broadband Phased Array Receiver

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Research in Astronomy and Astrophysics 2024年第4期24卷 60-70页

作者： Kai Wang Liang Cao Jun Ma Xue-Feng Duan Hao Yan Mao-zheng chen Yun-Wei Ning Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 8300lChina University of the Chinese Academy of Sciences Beijing 100049China Xinjiang Key Laboratory of Microwave Technology Urumqi 830011China

The receiver is a signal receiving device placed at the focus of the telescope.In order to improve the observation efficiency,the concept of phased array receiver has been proposed in recent years,which places a small phased array at the focal plane of the reflector,and flexible pattern and beam scanning functions can be achieved through a beamforming network.If combined with the element multiplexing,all beams within the entire field of view can be observed simultaneously to achieve continuous sky coverage.This article focuses on the front-end array of phased array receiver at 0.7-1.8 GHz for QiTai Telescope,and designs a Vivaldi antenna array of PCB structure with dual line polarization.Each polarization antenna is designed to arrange in a rectangle manner by 11×10.Based on the simulation results of the focal field,32,18,and eight elements were selected to form one beam at 0.7,1.25,and1.8 GHz.An analog beamforming network was constructed,and the measured gains of axial beam under uniform weighting were 19.32,13.72,and 15.22 dBi.Combining the beam scanning method of reflector antenna,the pattern test of different position element sets required for PAF beam scanning was carried out under independent array.The pattern optimization at 1.25 GHz was carried out by weighting method of conjugate field matching.Compared with uniform weighting,the gain,sidelobe level,and main beam direction under conjugate field matching have been improved.Although the above test and simulation results are slightly different,which is related to the passive array and laboratory testing condition,the relevant work has accumulated experience in the development of the front-end array for the phased array receiver,and has good guiding significance for future performance verification after the array is installed on the telescope.

关键词： telescopes instrumentation:detectors techniques:radar astronomy

PRaG 3.0 therapy for human epidermal growth factor receptor 2-positive metastatic pancreatic ductal adenocarcinoma:A case report

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World Journal of Gastroenterology 2024年第9期30卷 1237-1249页

作者： Yue-Hong Kong Mei-Ling Xu Jun-Jun Zhang Guang-Qiang chen Zhi-Hui Hong Hong Zhang Xiao-Xiao Dai Yi-Fu Ma Xiang-Rong Zhao chen-Yang Zhang Rong-zheng chen Peng-Fei Xing Li-Yuan Zhang Center for Cancer Diagnosis and Treatment The Second Affiliated Hospital of Soochow UniversitySuzhou 215000Jiangsu ProvinceChina Department of Radiotherapy&Oncology The Second Affiliated Hospital of Soochow UniversitySuzhou 215000Jiangsu ProvinceChina Institution of Radiotherapy&Oncology Soochow UniversitySuzhou 215000Jiangsu ProvinceChina Department of Radiology The Second Affiliated Hospital of Soochow UniversitySuzhou 215000Jiangsu ProvinceChina Department of Nuclear Medicine The Second Affiliated Hospital of Soochow UniversitySuzhou 215000Jiangsu ProvinceChina Department of Clinical Laboratory The Second Affiliated Hospital of Soochow UniversitySuzhou 215000Jiangsu ProvinceChina Department of Pathology The Second Affiliated Hospital of Soochow UniversitySuzhou 215000Jiangsu ProvinceChina

BACKGROUND Pancreatic ductal adenocarcinoma(PDAC)is a highly fatal disease with limited effective treatment especially after first-line chemotherapy.The human epidermal growth factor receptor 2(HER-2)immunohistochemistry(IHC)positive is associated with more aggressive clinical behavior and shorter overall survival in PDAC.CASE SUMMARY We present a case of multiple metastatic PDAC with IHC mismatch repair proficient but HER-2 IHC weakly positive at diagnosis that didn’t have tumor regression after first-line nab-paclitaxel plus gemcitabine and PD-1 inhibitor treatment.A novel combination therapy PRaG 3.0 of RC48(HER2-antibody-drug conjugate),radio-therapy,PD-1 inhibitor,granulocyte-macrophage colony-stimulating factor and interleukin-2 was then applied as second-line therapy and the patient had confirmed good partial response with progress-free-survival of 6.5 months and overall survival of 14.2 month.She had not developed any grade 2 or above treatment-related adverse events at any point.Percentage of peripheral CD8^(+) Temra and CD4^(+) Temra were increased during first two activation cycles of PRaG 3.0 treatment containing radiotherapy but deceased to the baseline during the maintenance cycles containing no radiotherapy.CONCLUSION PRaG 3.0 might be a novel strategy for HER2-positive metastatic PDAC patients who failed from previous first-line approach and even PD-1 immunotherapy but needs more data in prospective trials.

关键词： Pancreatic ductal adenocarcinoma PRaG 3.0 therapy Human epidermal growth factor receptor 2 Novel combination therapy Case report

A Novel Angle of Arrival Tracking Method in Large-Scale-Array Systems

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China Communications 2022年第9期19卷 171-190页

作者： chen zheng Dekang Liu Xuhui Ding Xiangyuan Bu Zhongshan Zhang School of Information and Electronics Beijing Institute of TechnologyBeijing 100081China

In this paper,we investigate the problem of angle of arrival(AOA)tracking for the largescale array in terahertz(THz)communication,which has a large size and a narrow beam,highly demanding an accurate angle estimation.On the one hand,the system usually adopts a hybrid structure with limited radio-frequency(RF)chains,which increases the difficulty of angle estimation;on the other hand,the rapid mobility of users also brings new challenges to angle estimation.To address the above challenges,a two-stage tracking framework is proposed in this paper,which employs the random phase matrix and orthogonal long pilots in the first stage to reduce the complicated multi-user estimation to multiple single-user estimations,followed by using both wide and narrow beams in the second stage to serve high-speed and low-speed users.Furthermore,a generalized-approximated-message-passing(GAMP)method is proposed for facilitating a low-accuracy estimation of the angles,followed by adopting a modified expectation-maximization(EM)algorithm based phase estimation to unbiased estimate the instantaneous angle with the help of high-gain characteristics of the beams.The proposed structure can not only simplify the estimation complexity,but also improve the estimation accuracy due to its capability of transferring the non-linear problem of angle observation into a linear gaussian model.In addition,the Kalman tracking framework is employed for performing a continuous angle tracking.Numerical results show that the angle estimation based on the random phase matrix in the initial stage can obtain a high enough estimation accuracy,while the GAMP algorithm implemented in the second stage can quickly capture the angle range under the Rayleigh limit.The performance of the proposed EM-based tracking method is shown to outperform the traditional extended Kalman filter(EKF)method.

关键词： angle tracking hybrid MIMO communications analog matrix