检索结果-南通市图书馆

Chinese Physics B 2021年第12期30卷 167-174页

作者： Geng Zhang da-Dong tian College of Computer and Information Science Southwest UniversityChongqing 400715China College of Information Science and Engineering Shandong Agricultural UniversityTai’an 271018China

Under the environment of vehicle-to-vehicle(V2V)communication,the traffic information on a large scale can be obtained and used to coordinate the operation of road traffic *** this paper,a new traffic lattice hydrodynamic model is proposed which considers the influence of multiple-lattice self-anticipative density integration on traffic flow in the V2V *** theoretical analysis,the linear stability condition of the new model is derived and the stable condition can be enhanced when more-preceding-lattice self-anticipative density integration effect is taken into *** property of the unstable traffic density wave in the unstable region is also studied according to the nonlinear *** is shown that the unstable traffic density wave can be described by solving the modified Korteweg-de-Vries(mKdV)***,the simulation results demonstrate the validity of the theoretical *** theoretical analysis and numerical simulations demonstrate that multiple-lattice self-anticipative density integration effect can enhance the stability of traffic flow system in the V2V environment.

关键词： lattice hydrodynamic model traffic stability self-anticipative density integration mKdV equation

Internet worm early detection and response mechanism

在线全文

学校读者我要写书评

暂无评论

The Journal of China Universities of Posts and Telecommunications 2007年第3期14卷 79-84页

作者： WANG Jian LIU Yan-heng tian da-xin WEI da College of Computer Science and Technology Jilin UniversityChangchun 130012 China

In recent years, fast spreading worm has become one of the major threats to the security of the Internet and has an increasingly fierce tendency. In view of the insufficiency that based on Kalman filter worm detection algorithm is sensitive to interval, this article presents a new data collection plan and an improved worm early detection method which has some deferent intervals according to the epidemic worm propagation model, then proposes a worm response mechanism for slowing the wide and fast worm propagation effectively. Simulation results show that our methods are able to detect worms accurately and early.

关键词： worm early detection Kalman filter worm propagation model

A Hybrid Time-delay Prediction Method for Networked Control System

在线全文

学校读者我要写书评

暂无评论

International Journal of Automation and computing 2014年第1期11卷 19-24页

作者： Zhong-da tian Xian-Wen Gao Kun Li School of Information Science & Engineering Northeastern University

This paper presents an Ethernet based hybrid method for predicting random time-delay in the networked control ***,db3 wavelet is used to decompose and reconstruct time-delay sequence,and the approximation component and detail components of time-delay sequences are fgured ***,one step prediction of time-delay is obtained through echo state network(ESN)model and auto-regressive integrated moving average model(ARIMA)according to the diferent characteristics of approximate component and detail ***,the fnal predictive value of time-delay is obtained by ***,the parameters of echo state network is optimized by genetic *** simulation results indicate that higher accuracy can be achieved through this prediction method.

关键词： Networked control system wavelet transform auto-regressive integrated moving average model echo state network genetic algorithm time-delay prediction

Production and characterization of high porosity porous Fe?Cr?C alloys by the space holder leaching technique

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2016年第7期23卷 793-798页

作者： da-rong tian Yu-hua Pang Liang Yu Li Sun School of Metallurgical Engineering Xi'an University of Architecture and TechnologyXi'an 710055China Research Center of Metallurgical Engineering and Technology of Shaanxi Province Xi'an 710055China AVIC Xi'an Aircraft Industry(Group)Company Ltd. Xi'an 710000China

Spherical carbamide particles were employed to produce porous Fe–Cr–C alloy with high porosity and large aperture via the space-holder leaching technique. A series of porous samples were prepared by regulating the processing parameters, which included the carbamide content and the compaction pressure. The pore characteristics and compression properties of the produced samples were investigated. The samples were characterized by scanning electron microscopy, image analysis, and compression tests. The results showed that the macro-porosity and the mean pore size were in the ranges 40.4%–82.4% and 0.6–1.5 mm, respectively. The compressive strength varied between 25.38 MPa and 127.9 MPa, and was observed to decrease with increasing total porosity.

关键词： porous metal powder metallurgy cellular manufacturing porosity compressive strength

Time-delay Compensation Method for Networked Control System Based on Time-delay Prediction and Implicit PIGPC

在线全文

学校读者我要写书评

暂无评论

International Journal of Automation and computing 2015年第6期12卷 648-656页

作者： Zhong-da tian Xian-Wen Gao Bi-Lian Gong Tong Shi School of Information Science and Engineering Shenyang University of Technology School of Information Science and Engineering Northeastern University Department of Humanities Liaoning Forestry Vocation-Technical College

A network time-delay compensation method based on time-delay prediction and implicit proportional-integral-based generalized predictive controller(PIGPC) is proposed. The least squares support vector machine(LSSVM) is used to predict the current time-delay, the parameters of the least squares support vector machine are optimized by particle swarm optimization(PSO) algorithm,and the predicted time-delay is used instead of the actual time-delay as the parameters of the network time-delay compensation controller. In order to improve the compensation effect of implicit generalized predictive controller(GPC), this paper puts forward an implicit generalized predictive control algorithm with proportional-integral-based(PI) structure and designs the controller based on implicit PIGPC. Through the simulation results, the effectiveness of this design in the paper is verified.

关键词： Networked control system time-delay compensation p

Primitive neuroectodermal tumor of the prostate in a 58-year-old man:A case report

在线全文

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2022年第13期10卷 4145-4152页

作者： da-Wei tian Xiao-Chun Wang Hui Zhang Yan Tan College of Medical Imaging Shanxi Medical UniversityTaiyuan 030001Shanxi ProvinceChina Department of Radiology The First Hospital of Shanxi Medical UniversityTaiyuan 030001Shanxi ProvinceChina

BACKGROUND Primitive neuroectodermal tumor(PNET),especially located in the prostate,is a rare tumor that mainly occurs in young *** or rectum invasion and distant metastasis are strongly associated with a poor *** therapy,including radical surgery,adjuvant chemotherapy,and radiotherapy,is *** present a case of prostatic PNET and a review of 17 cases identified in the *** SUMMARY A 58-year-old man was admitted complaining of dysuria for 2 *** tomography and magnetic resonance imaging showed a large cystic-solid mass in the pelvic cavity compressing the surrounding bladder and *** mass was iso-to hyperintense on T1-weighted imaging(WI)and heterogeneously hyperintense on *** degeneration and necrosis were seen in the tumor,and solid tissues within the mass enhanced on contrast-enhanced *** patient underwent robot-assisted laparoscopic pelvic tumor ***,the presence of many small round cells that were positive for expression of CD99,vimentin,and synaptophysin established the diagnosis of PNET in the prostate after *** patient underwent adjuvant *** 34 mo of follow-up,the patient had no signs or symptoms of recurrence or residual *** We present the case of the oldest prostatic PNET patient,who has a good *** illustrates how older men with prostatic PNET may also benefit from the combination therapy,like younger adults,and achieve a long-term *** always,PNET should be considered in the differential diagnosis of aggressive prostatic tumors in young men.

关键词： Primitive neuroectodermal tumor Prostate Combination therapy Magnetic resonance imaging CD99 Case report

Molecular evolution of pancreatic ribonuclease gene(RNase1)in Rodentia

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 Genetics and Genomics 2017年第4期44卷 219-222页

作者： da-tian Lang Xiao-Ping Wang Lei Wang Li Yu Chemistry and Life Science Department Zhaotong UniversityZhaotong 657000China state key laboratory for conservation and utilization of bio-resource in yunnan yunnan universitykunming 650091china key laboratory for animal genetic diversity and evolution of high education in yunnan province yunnan universitykunming 650091china

Pancreatic ribonuclease,which is encoded by RNase1,is a digestive enzyme secreted by the pancreas of vertebrates,and has been recognized to be a classic example for molecular evolutionary studies due to the frequent occurrence of gene duplication and functional divergence in organisms（Zhang et al.,2002,2006;Yu and Zhang,2006;Yu et al.,2010;Xu et al.,2013;Liu et al.,2014）.RNase1 has been extensively studied in many mammals,

关键词： RNase in Rodentia classic divergence digestive evolutionary duplication pancreas branch clade

Effects of Bacterial-Feeding Nematode Grazing and Tea Saponin Addition on the Enhanced Bioremediation of Pyrene-Contaminated Soil Using Polycyclic Aromatic Hydrocarbon-Degrading Bacterial Strain

在线全文

学校读者我要写书评

暂无评论

Pedosphere 2017年第6期27卷 1062-1072页

作者： SUN Mingming LIU Kuan ZHAO Yuanchao tian da YE Mao LIU Manqiang JIAO Jiaguo JIANG Xin Soil Ecology Lab College of Resources and Environmental SciencesNanjing Agricultural UniversityNanjing 210092(China) Key Laboratory of Soil Environment and Pollution Remediation Institute of Soil ScienceChinese Academy of SciencesNanjing 210008(China)

As one of the most widely distributed bacterial predators in the soil, the role of bacterivorous nematodes on the enhanced bioremediation of polycyclic aromatic hydrocarbon-contaminated soils is crucial, but remains to be investigated.A microcosm-level study was conducted to examine the effects of bacterial-feeding nematode grazing and tea saponin(TS) addition on bioremediation of a pyrene-contaminated soil enhanced by the polycyclic aromatic hydrocarbon(PAH)-degrading bacterial strain Sphingobium *** 180 d of incubation, the highest pyrene dissipation(71.3%) was achieved through a combination of Sphingobium ***9 inoculation with nematode and TS ***, high counts of culturable PAH-degrading bacteria, soil enzyme activity, and biodiversity indices were observed under the combined treatment, implying that the microbiological function of the contaminated soil was significantly ***, the results of Tenax~ extraction with the first-order three-compartment model indicated that rate-limiting factors varied among *** lack of degrading microorganisms was the main rate-limiting factor for the treatments involving TS/nematode addition, and inadequate bioaccessible pyrene was the vital rate-limiting factor in the treatments involving Sphingobium ***9 *** proposed combined clean-up strategy proved to be a promising bioremediation technology for aged pyrene-contaminated soils.

关键词： desorbing fraction desorption rate constant physiological profile of soil microbial community Shannon-Weaver index Simpson index soil microbial activity Sphingobium sp.PHE9

Heterogeneous Mediator Enabling Three-Dimensional Growth of Lithium Sulfide for High-Performance Lithium-Sulfur Batteries

在线全文

学校读者我要写书评

暂无评论

Energy & Environmental Materials 2022年第4期5卷 1214-1221页

作者： da tian Xueqin Song Yue Qiu Xun Sun Bo Jiang Chenghao Zhao Yu Zhang Xianzhu Xu Lishuang Fan Naiqing Zhang School of Chemistry and Chemical Engineering Harbin Institute of TechnologyHarbin 150001China Academy of Fundamental and Interdisciplinary Sciences Harbin Institute of TechnologyHarbin 150001China State Keys Laboratory of Urban Water Resource and Environment Harbin Institute of TechnologyHarbin 150001China

Two-dimensional(2D)deposition regime of insulating lithium sulfide(Li_(2)S)is a major obstacle to achieve high reversible capacity in the conventional glyme-based lithium-sulfur(Li-S)batteries as it leads to rapid loss of active electrode surface and low sulfur *** three-dimensional(3D)growth of Li_(2)S is therefore considered to be necessary,but the available strategies are mainly based on the electrolyte manipulations,which inevitably lead to added complexity of the electrode-electrolyte compatibility and,in particular,instability of the lithium *** this work,we have developed a heterogeneous polysulfide mediator composed of discrete Mo_(5)N_(6) anchored on graphene,which functions on the cathode side,to regulate the deposition mode of Li_(2)***_(5)N_(6) can efficiently boost the formation of Li_(2)S as demonstrated by a series of experimental and computational *** importantly,the discrete distribution of Mo_(5)N_(6) nucleants on graphene postpones the merging of adjacent Li_(2)S nuclei to promote their isotropic ***,3D deposits of Li_(2)S is guided by the heterogeneous *** from these unique superiorities,Li-S cells with high rate capability of 954 mAh g^(-1) at 2 C and long cycle life exceeding 1000 cycles are realized without advanced lithium anode protection.

关键词： electrocatalysis lithium sulfide nucleation lithium-sulfur batteries polysulfide redox reaction shuttle effect

对偶性和线性规划问题的神经网络解法(英文)

在线全文

学校读者我要写书评

暂无评论

自动化学报 2003年第2期29卷 219-226页

作者：田大钢上海理工大学管理学院上海200093

通过一种新的对偶形式 ,得到一种新的易于实现的解线性规划问题的神经网络 ,证明了网络具有全局指数收敛性 ,使得线性规划问题的神经网络解法趋于完善 .

关键词：偶性线性规划神经网络解法全局指数收敛性