检索结果-南通市图书馆

Novel high-safety aeroengine performance predictive control method based on adaptive tracking weight

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

Chinese Journal of Aeronautics 2024年第7期37卷 352-374页

作者： Qian CHEN Hanlin sheng jie zhang Jiacheng LI College of Energy and Power Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China College of Automation Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China

Increasing attention has been attracted to the dynamic performance and safety of advanced performance predictive control systems of the next-generation *** latest research demonstrates that Subspace-based Improved Model Predictive Control(SIMPC)can overcome the difficulty in solving the predictive model in MPC/NMPC ***,applying constant design parameters cannot maintain consistent control effects in all ***,the designed system relies too much on sensor-measured data,and thus it is difficult to thoroughly validate the safety of the system because of its high *** means that any potential hardware/software faults will endanger the ***,this paper first presents a novel nonlinear mapping relationship to adaptively tune the tracking weight online with the change of Power Lever Angle(PLA)and real-time relative tracking ***,without introducing additional design parameters,an Adaptive Tracking Weight-based SIMPC(ATW-SIMPC)controller is designed to improve the control performance in all operating states ***,a Primary/Backup Hybrid Control(PBHC)strategy with the ATW-SIMPC controller as the primary system and the traditional speed(Nf)controller as the backup system is proposed to ensure *** designed affiliated switching controller and the real-time monitor therein can be used to realize reasonable and smooth switching between primary/backup systems,so as to avoid bump *** PBHC system switches to the Nf controller when the ATW-SIMPC controller is wrong because of potential hardware/software faults;otherwise,the ATW-SIMPC controller keeps acting on the *** main results prove that the ATW-SIMPC controller with the optimal nonlinear mapping relationship,compared with the existing SIMPC controller,uplifts the dynamic control performance by 32%and reduces overshoots to an allowable limit,resulting in a better control effect in full *** comparison results consistently i

关键词： Aeroengine Model predictive control Hybrid system Adaptive weight Safety

Neoadjuvant chemoradiotherapy for resectable esophageal carcinoma:A meta-analysis

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2009年第47期15卷 5983-5991页

作者： Hai-Lin Jin Hong Zhu Ting-sheng Ling Hong-jie zhang Rui-Hua Shi Department of Gastroenterology the First Affiliated Hospital of Nanjing Medical University Nanjing 210029 Jiangsu Province China

AIM:To compare neoadjuvant chemoradiotherapy and surgery with surgery alone for resectable esophageal carcinoma. METHODS:We used MEDLINE and EMBASE databases to identify eligible studies and manual searches were done to ensure no studies were *** validity assessment was performed and a trial quality score was assigned. RESULTS:Eleven randomized controlled trials(RCTs) including 1308 patients were *** chemoradiotherapy significantly improved the overall survival compared with surgery *** ratio(OR) [95%confidence interval(CI),P value],expressed as neoadjuvant chemoradiotherapy and surgery vs surgery alone,was 1.28(1.01-1.64,P=0.05)for 1-year survival,1.78(1.20-2.66,P=0.004)for 3-year survival,and 1.46(1.07-1.99,P=0.02)for 5-year *** mortality increased in patients treated by neoadjuvant chemoradiotherapy(OR: 1.68,95%CI:1.03-2.73,P=0.04),but incidence of postoperative complications was similar in two groups (OR:1.14,95%CI:0.88-1.49,P=0.32).Neoadjuvant chemoradiotherapy lowered the local-regional cancer recurrence(OR:0.64,95%CI:0.41-0.99,P=0.04), but incidence of distant cancer recurrence was similar (OR:0.94,95%CI:0.68-1.31,P=0.73).Histological subgroup analysis indicated that esophageal squamous cell carcinoma did not benefit from neoadjuvantchemoradiotherapy,OR(95%CI,P value)was 1.16(0.85-1.57,P=0.34)for 1-year survival,1.34 (0.98-1.82,P=0.07)for 3-year survival and 1.41 (0.98-2.02,P=0.06)for 5-year survival. CONCLUSION:Neoadjuvant chemoradiotherapy can raise the survival rate of patients with esophageal adenocarcinoma.

关键词： Esophageal carcinoma Neoadjuvant chemoradiotherapy Randomized controlled trial Metaanalysis

Design of Nonlinear Decoupling Controller for Double-electromagnet Suspension System

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

自动化学报 2006年第3期32卷 321-328页

作者： LIU De-sheng LI jie zhang Kun College of Mechatronics Engineering and Automation National University of Defense Technology Changsha 410073

Aiming at the coupling characteristic between the two groups of electromagnets embedded in the module of the maglev train, a nonlinear decoupling controller is designed. The module is modeled as a double-electromagnet system, and based on some reasonable assumptions its nonlinear mathematical model, a MIMO coupling system, is derived. To realize the linearization and decoupling from the input to the output, the model is linearized exactly by means of feedback linearization, and an equivalent linear decoupling model is obtained. Based on the linear model, a nonlinear suspension controller is designed using state feedback. Simulations and experiments show that the controller can effectually solve the coupling problem in double-electromagnet suspension system.

关键词：双倍电磁体解耦悬浮控制器反馈控制器

Identification of biomarkers for cervical cancer in peripheral blood lymphocytes using oligonucleotide microarrays

在线全文

学校读者我要写书评

暂无评论

Chinese Medical Journal 2010年第8期123卷 1000-1005页

作者： sheng jie zhang Wei-yuan Department of Gynecology Beijing Obstetrics and Gynecology Hospital Capital Medical University Beijing 100026 China

Background Oligonucleotide microarrays are increasingly being used to identify gene expression profiles that associated with complex genetic diseases. Peripheral lymphocytes communicate with cells and extracellular matrixes in almost all tissues and organs in human body, suggesting that the gene expression profiles in peripheral lymphocytes may reflect the presence of disease in the body. This study aimed to identify molecular biomarkers for cervical cancer in peripheral blood lymphocytes by using oligonucleotide microarrays. Methods Total RNA was extracted from peripheral blood lymphocytes of 24 early stage cervical cancer patients and 18 healthy controls. We used 22K Human Genome microarrays to profile peripheral blood lymphocytes from 4 early stage cervical cancer patients and compared their gene expression profiles with those from 3 healthy controls. Differentially expressed genes would be identified if they had adjusted P values of less than 0.05 and a groupwise average fold change greater than 1.5 or less than 0.67. Then the selected 5 genes were validated in the remaining 20 early stage cervical cancer patients and the 15 healthy controls by using real-time reverse-transcription polymerase chain reaction （RT-PCR）. Results Genes identified by the gene selection program expressed differently between the blood samples of the early stage cervical cancer patients and those of the healthy controls. To validate the gene expression data, 5 genes were analyzed by real-time RT-PCR. In three of the 5 identified genes, tenasin-c （TNC）, nuceolin （NCL）, and enolase 2 （EN02） showed a significant up-regulation in the blood samples of the early stage cervical cancer patients versus that of the healthy controls. Conclusions The up-regulation of TNC, NCL, and EN02 in peripheral blood may be used to identify novel blood biomarkers for detecting cervical cancer in a clinically accessible surrogate tissue, and thus to provide a possibility to develop a noninvasive and predictive d

关键词： uterine cervical neoplasms biomarkers peripheral lymphocyte microarrays

Single-structure 3-axis Lorentz force magnetometer based on an AlN-on-Si MEMS resonator

在线全文

学校读者我要写书评

暂无评论

Microsystems & Nanoengineering 2024年第3期10卷 75-86页

作者： Cheng Tu Xu-heng Ou-Yang Ying-jie Wu Xiao-sheng zhang School of Integrated Circuit Science and Engineering University of Electronic Science and Technology of ChinaChengdu 611731China

This work presents a single-structure 3-axis Lorentz force magnetometer(LFM)based on an AlN-on-Si MEMS *** operation of the proposed LFM relies on the flexible manipulation of applied excitation currents in different directions and frequencies,enabling the effective actuation of two mechanical vibration modes in a single device for magnetic field measurements in three ***,the excited out-of-plane drum-like mode at 277 kHz is used for measuring the x-and y-axis magnetic fields,while the in-plane square-extensional mode at 5.4 MHz is used for measuring the z-axis magnetic *** different configurations of applied excitation currents ensure good crossinterference immunity among the three *** to conventional capacitive LFMs,the proposed piezoelectric LFM utilizes strong electromechanical coupling from the AlN layer,which allows it to operate at ambient pressure with a high *** understand and analyze the measured results,a novel equivalent circuit model for the proposed LFM is also reported in this work,which serves to separate the effect of Lorentz force from the unwanted capacitive *** demonstrated 3-axis LFM exhibits measured magnetic responsivities of 1.74 ppm/mT,1.83 ppm/mT and 6.75 ppm/mT in the x-,y-and z-axes,respectively,which are comparable to their capacitive counterparts.

关键词： resonator Lorentz structure

Enhancing microseismic/acoustic emission source localization accuracy with an outlier-robust kernel density estimation approach

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

International Journal of Mining Science and Technology 2024年第7期34卷 943-956页

作者： jie Chen Huiqiong Huang Yichao Rui Yuanyuan Pu sheng zhang Zheng Li Wenzhong Wang State Key Laboratory of Coal Mine Disaster Dynamics and Control Chongqing UniversityChongqing 400044China School of Resources and Safety Engineering Chongqing UniversityChongqing 400044China School of Resources and Safety Engineering Central South UniversityChangsha 410083China Chongqing City Construction Investment Group Co. Ltd.Chongqing 400023China Coal Geological Exploration Institute of Gansu Lanzhou 730000China

Monitoring sensors in complex engineering environments often record abnormal data,leading to significant positioning *** reduce the influence of abnormal arrival times,we introduce an innovative,outlier-robust localization method that integrates kernel density estimation(KDE)with damping linear correction to enhance the precision of microseismic/acoustic emission(MS/AE)source *** approach systematically addresses abnormal arrival times through a three-step process:initial location by 4-arrival combinations,elimination of outliers based on three-dimensional KDE,and refinement using a linear correction with an adaptive damping *** validate our method through lead-breaking experiments,demonstrating over a 23%improvement in positioning accuracy with a maximum error of 9.12 mm(relative error of 15.80%)—outperforming 4 existing *** under various system errors,outlier scales,and ratios substantiate our method’s superior *** blasting experiments also confirm the practical applicability,with an average positioning error of 11.71 m(relative error of 7.59%),compared to 23.56,66.09,16.95,and 28.52 m for other *** research is significant as it enhances the robustness of MS/AE source localization when confronted with data *** also provides a practical solution for real-world engineering and safety monitoring applications.

关键词： Microseismic source/acoustic emission(MS/AE) Kernel density estimation(KDE) Damping linear correction Source location Abnormal arrivals

High-temperature oxidation resistance of Si-coated C/SiC composites

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2024年第9期43卷 4566-4572页

作者： jie Xiao Hua-Yue zhang sheng-Kai Gong Hui-Bin Xu Hong-Bo Guo School of Materials Science and Engineering Beihang UniversityBeijing 100191China Key Laboratory of High-Temperature Structure Materials and Protective Coatings(Ministry of Industry and Information Technology) Beihang UniversityBeijing 100191China

In this paper,Si coatings were sprayed onto C/SiC composite substrates by atmospheric plasma spraying(APS).The high-temperature oxidation behavior of the substrate and coating at temperatures of 1100 and 1300℃was also *** C/SiC ceramic matrix composite will be damaged seriously and even failed due to the oxidation of carbon fibers in *** Si coating effectively improved the oxidation resistance of the C/SiC substrate in the high-temperature oxidation *** effect of the thickness of the Si coatings on the oxidation resistance was *** 150-μm coating is proved to enable the substrate to have the lowest oxidation weight loss and the best oxidation resistance after static oxidation for 5 h.

关键词： Ceramic matrix composites(CMCs) Carbon fiber Si coating Oxidation Plasma spray

Multiple damage zones around hydraulic fractures generated by high-frequency pulsating hydraulic fracturing

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2024年第4期21卷 2688-2702页

作者： Yan Peng sheng-jie Wei Guang-Qing zhang Da-Wei Zhou Chuang-Chao Xu School of Petroleum Engineering China University of Petroleum PetroChina Changqing Oilfield Company

Pulsating hydraulic fracturing(PHF) is a promising fracturing method and can generate a dynamic periodic pressure. The periodic pressure can induce fatigue failure of rocks and decrease initiation pressure of fracture. If the frequency of periodic pressure exceeds 10 Hz, the distribution of pressure along the main fracture will be heterogeneous, which is much different from the one induced by the common fracturing method. In this study, the impact of this special spatial feature of pressure on hydraulic fracture is mainly investigated. A coupled numerical simulation model is first proposed and verified through experimental and theoretical solutions. The mechanism of secondary fracture initiation around the main fracture is then discovered. In addition, sensitivity studies are conducted to find out the application potential of this new method. The results show that(1) this coupled numerical simulation model is accurate. Through comparison with experimental and theoretical data, the average error of this coupled model is less than 1.01%.(2) Even if a reservoir has no natural fracture, this heterogeneous distribution pressure can also cause many secondary fractures around the main fracture.(3) The mechanism of secondary fracture initiation is that this heterogeneous distribution pressure causes tensile stress at many locations along the main fracture.(4) Through adjusting the stimulation parameters, the stimulation efficiency can be improved. The average and amplitude of pressure can increase possibility of secondary fracture initiation. The frequency of this periodic pressure can increase number of secondary fractures. Even 6 secondary fractures along a 100 m-length main fracture can be generated.(5) The influence magnitudes of stimulation parameters are larger than ones of geomechanical properties, therefore, this new fracturing method has a wide application potential.

关键词： Tight reservoir Reservoir stimulation Numerical simulation Secondary fracture Fracture initiation

Slicing capacity-centered mode selection and resource optimization for network-assisted full-duplex cell-free distributed massive MIMO systems

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2024年第1期67卷 203-220页

作者： jie WANG Jiamin LI Pengcheng ZHU Dongming WANG Hongbiao zhang Yue HAO Bin sheng National Mobile Communications Research Laboratory Southeast University 2. Purple Mountain Laboratories China Mobile Research Institute

Network-assisted full-duplex(NAFD) cell-free distributed massive multiple-input multipleoutput(MIMO) systems enable uplink(UL) and downlink(DL) communications within the same timefrequency resources,which potentially reduce latency by avoiding the overhead of switching UL/DL ***,how to choose UL/DL modes remains an important factor affecting system *** the dramatic increase in the number of users and access points(APs),massive access brings significant overhead in the mode ***,the different quality of service(QoS) among users also makes the effective utilization of resources *** one of the most promising technologies in sixth-generation(6G),network slicing enables the adaptive configuration of limited UL/DL resources through the resource isolation assisted NAFD ***,we propose a slicing capacity-centered *** this scheme,APs are motivated by slicing requirements and associated slices to form different *** mode selection and resource allocation are performed within each subsystem to reduce overhead and improve resource *** implement this scheme efficiently,a double-layer deep reinforcement learning(DRL)mechanism is used to realize the joint optimization of mode selection and resource *** results show that the slicing capacity-centered scheme can effectively improve resource utilization and reduce overhead.

关键词： network-assisted full-duplex network slicing mode selection resource optimization deep reinforcement learning