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THz Channel Modeling: Consolidating the Road to THz Communications

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China Communications 2021年第5期18卷 33-49页

作者： Shanyun Liu Xianbin Yu Rongbin Guo Yajie Tang zhifeng zhao Zhejiang Laboratory Hangzhou 311121China

For the sake of meeting the demand of data rates at terabit(Tbit)per second scale in future networks,the terahertz(THz)band is widely accepted as one of the potential key enabling technologies for next generation wireless communication *** the progressive development of THz devices,regrading THz communications at system level is increasing crucial and captured the interest of plenty of *** this scope,THz channel modeling serves as an indispensable and fundamental *** surveying the latest literature findings,this paper reviews the problem of channel modeling in the THz band,with an emphasis on molecular absorption loss,misalignment fading and multipath fading,which are major influence factors in the THz channel ***,we focus on simulators and experiments in the THz band,after which we give a brief introduction on applications of THz channel models with respects to capacity,security,and sensing as ***,we discuss some key issues in the future THz channel modeling.

关键词： terahertz(THz) channel modeling survey sixth-generation(6G) molecular absorption loss misalignment fading multipath fading

Association of endothelial nitric oxide synthase polymorphisms with an increased risk of erectile dysfunction

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Asian Journal of Andrology 2017年第3期19卷 330-337页

作者： Lei Gao zhifeng zhao Fengfu Guo Yan Liu Jianhua Guo Yang zhao Zhong Wang Department of Urinary Surgery Linyi People's Hospital Linyi 276000 China Department of Urinary Surgery Linyi Cancer Hospital Linyi 276000 China Department of Urology and Andrology Ninth People's Hospital School of Medicine Shanghai Jiao Tong University Shanghai 200011 China Department of Urology Shanghai Pudong Hospital Fudan University Pudong Medical Centre Shanghai 200011 China.

The purpose of our meta-analysis is to examine the associations between three single nucieotide polymorphisms of endothelial nitric oxide synthase （eNOS） gene, G894T, intron 4 and T-786C, and the risk of erectile dysfunction. An electronic database search was performed to identify case-control studies reporting the association between single nucleotide polymorphisms of eNOS gene and erectile dysfunction. Stringent inclusion and exclusion criteria were employed to select high-quality studies for this meta-analysis. Comprehensive Meta-analysis 2.0 software （Biostat Inc., Englewood, New Jersey, USA） was used for statistical analysis of the data extracted from the selected studies. From the initial 203 articles retrieved from database search, this meta-analysis finally selected 12 high-quality case-control studies that conformed to our inclusion criteria. The 12 studies contained a total of 1962 patients with erectile dysfunction and 1752 healthy controls. The results of our meta-analysis showed that G894T correlated with an increased risk erectile dysfunction under both the allele and dominant models （allele： OR = 1.556, 95% CI -- 1.064-2.275, P = 0.023; dominant： OR = 1.613, 95% CI = 1.050-2.476, P = 0.029）. A similar association was found between T-786C and erectile dysfunction under the allele model （OR = 1.679, 95% CI = 1.341-2.102, P 〈 0.001）, but not under the dominant model （all P 〉 0.05）. Our meta-analysis showed that the two single nucleotide polymorphisms in eNOS gene, G894T and T-786C, are strongly associated with the risk of erectile dysfunction.

关键词： endothelial nitric oxide synthase erectile dysfunction G894T intron 4 meta-analysis single nucleotide polymorphism

Design of omnidirectional steepest roll control law for vertical launching missile 36

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Design of omnidirectional steepest roll control law for vert...

Simultaneous Identification of Vehicular Parameters and Structural Damages in Bridge

第36届中国控制会议

作者： Qinhong Tang Jiufen zhao Shaokun shi zhifeng zhao Xi’an Research Institute of Hi-Tech

ISBN: (纸本)9781538629185

A new type of anti-tank missile is studied,and the Magnus effect of roll-to-yaw channel in the process of turning is *** the condition of rapid response of composite linkage servo,the theory and engineering method of vertical launching which apply to the projectile quickly and accurately complete initial segment turning and all-round flight is *** this paper,the guidance control model of missile’s omnidirectional launch is established,and the optimal control law of roll angle based on minimum principle is *** the constraints of the projectile and steering gear,an optimal model of the roll angle control function which is suitable for engineering practice is *** results show that the projectile can roll in all directions at a faster speed in accordance with the designed roll angle control law based on the time required to ensure the stability of the missile attitude,which achieves the projectile roll in the air that required to complete all-round launch and it is proved that the proposed model is effective and reliable.

关键词： All-round launch Optimal roll angle Guidance control model Minimum principle Optimal control law

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Wuhan University Journal of Natural Sciences 2018年第1期23卷 84-92页

作者： ZHANG Xiaozhong SUN Guomin SUN Yanhua zhao zhifeng School of Civil and Architectural Engineering Guizhou University of Engineering Science

In this paper, we present a method for simultaneously identifying the vehicular parameters and the structural damage of bridges. By using the dynamic response data of bridge in coupled vibration state and the algorithm for the inverse problem, the vehicle-bridge coupling model is built through combining the motion equations of both vehicle and the bridge based on their interaction force relationship at contact point. Load shape function method and Newmark iterative method are used to solve the vibration response of the coupled system. Penalty function method and regularization method are interchangeable in the process until the error is less than the allowable value. The proposed method is applied on a single-span girders bridge, and the recognition results verify the feasibility, high accuracy and robustness of the method.

关键词： vehicle-bridge coupling model vehicular parameters structural damage in bridges identification method simultaneously recognition accuracy better robustness

Research on a New Method of Facial Feature Extraction 36

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Research on a New Method of Facial Feature Extraction

Phthalocyanine-supported single-atom catalysts as a promising bifunctional electrocatalyst for ORR/OER: A computational study

第36届中国控制会议

作者： Donglin Xue Jiufen zhao Qinhong Tang Shaokun Shi zhifeng zhao Xi’an Research Institute of Hi-Tech

ISBN: (纸本)9781538629185

In order to find a set of optimal discriminant vectors which can maximize the inter-class scatter while simultaneously minimizing the intra-class scatter after the projection,a new algorithm of orthogonal optimal discriminant vectors and a new algorithm of statistically uncorrelated optimal discriminant vectors for feature extraction were *** with the original MMC feature extraction method,the new feature extraction method greatly eliminates the statistical correlation between the best discriminant vectors and improves the recognition *** experiment results on Olivetti Research Laboratory（ORL）face database shows that the new feature extraction method of statistically uncorrelated maximum margin criterion（SUMMC）are better in terms of recognition rate and ***,the relation between maximum margin criterion and Fisher criterion for feature extraction were revealed.

关键词： optimal discriminant vectors maximum margin criterion statistically correlation feature extraction face recognition

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ChemPhysMater 2022年第3期1卷 237-245页

作者： Xinyi Li Zhongxu Wang Zhanhua Su zhifeng zhao Qinghai Cai Jingxiang zhao College of Chemistry and Chemical Engineering Key Laboratory of Photonic and Electronic Bandgap MaterialsMinistry of EducationHarbin Normal UniversityHarbin 150025China College of Chemistry Guangdong University of Petrochemical TechnologyMaoming 525000China Heilongjiang Province Collaborative Innovation Center of Cold Region Ecological Safety Harbin 150025China

Developing excellent performance catalysts for the oxygen reduction reaction(ORR)and oxygen evolution re-action(OER)is fundamental for the commercialization of energy transduction and storage *** our works,the potential of plenty of transition metals(TMs)anchored on phthalocyanine(TM-Pc)(TM=Sc,Ti,V,Cr,Mn,Fe,Co,Ni,Cu,Zn,Mo,Ru,Rh,Pd,Ag,Re,Os,Ir,and Pt)as electrocatalysts for the ORR/OER was sys-tematically explored through synthetic density functional theory(DFT)*** TM-Pc candidates exhibited high electrochemical stability owing to the intense binding among the anchored TM and the Pc-based ***,the free energy profiles showed that Ir-Pc can be performed as an outstanding bifunc-tional electrocatalyst for ORR/OER due to its ultralow overpotentials(𝜂ORR=0.46 V and𝜂OER=0.23 V),which can be reasonably explained by energetic and electronic *** present findings not only expand the database of single-atom catalysts(SACs),but also open the way for the reasonable design and development of advanced electrocatalysts for renewable energy technology.

关键词： Oxygen reduction/evolution Single-atom catalysts Phthalocyanine Density functional theory

Simulation Study of Diesel Spray Tilt Angle and Ammonia Energy Ratio Effect on Ammonia-Diesel Dual-Fuel Engine Performance

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Energy Engineering 2024年第9期121卷 2603-2620页

作者： zhifeng zhao Xuelong Miao Xu Chen Jinbao Zheng Yage Di Zhenjie Bao Zhuo Yang Mechanical and Automotive Engineering School Shanghai University of Engineering ScienceShanghai201620China

Ammonia-diesel dual fuel(ADDF)engines for transportation applications are an important way to reduce carbon *** order to achieve better combustion of ammonia in diesel engines.A small-bore single-cylinder engine was converted into an ADDF engine with the help of mature computational fluid dynamics(CFD)simulation software to investigate the performance of an engine with a high ammonia energy ratio(AER),and to study the effect of spray tilt angle on ADDF *** results showed that the increase in AER reduced nitric oxide(NO)and nitrogen dioxide(NO2)emissions but increased nitrous oxide(N2O)and unburned ammonia *** in the range of 50%-70%achieved lower greenhouse gases(GHG)emissions than the pure diesel *** to the pure diesel mode,when the AER was 60%,the indicated thermal efficiency(ITE)was increased by 0.2%and the GHG emissions were decreased by 22.3%,but carbon monoxide(CO)and Hydrocarbon(HC)emissions were *** the in-cylinder combustion temperature or high-temperature region range of the ADDF engine could reduce GHG *** an AER of 60%,an increase in the spray tilt angle helped the ammonia combustion in the residual gap to reduce the unburned ammonia *** to the pure diesel mode with a spray tilt angle of 75°,an AER of 60%with a spray tilt angle of 77.5°improved the ITE by 1.5%,and reduced theGHGemissions by 25.7%.Adjusting the spray tilt angle of theADDFengine also *** is an effective way to improve ADDF engine performance by adjusting the spray tilt angle.

关键词： Ammonia-diesel engine ammonia energy ratio greenhouse gases carbon-free fuel

Effect of Titanium,Antimony,Cerium and Carbon Nanotubes on the Morphology and Microhardness of Mg-based Icosahedral Quasicrystal Phase

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Journal of Materials Science & Technology 2010年第1期26卷 27-32页

作者： zhifeng Wang, Weimin zhao, Haipeng Li, Jian Ding, Yongyan Li and Chunyong Liang School of Materials Science and Engineering, Hebei University of Technology, Tianjin 300130, China [a] School of Materials Science and Engineering Hebei University of Technology Tianjin 300130 China

For the first time, petal-like and spherical Mg-based icosahedral quasicrystal phase （I-phase） were obtained by introducing Ti, Sb, Ce and C nanotubes into Mg-Zn-Y alloy under normal casting conditions. The formation mechanism and stability criterion of spherical I-phase were discussed. The morphology and microhardness of I-phase and their determinants were studied in this paper. The results show that the different value of microhardness of I-phase could be attributed to the different kinds of the fourth component and its content, and its different innate characters. The final morphology of icosahedral quasicrystalline （IQC） is decided by the size of critical stable radius Rr, the content of the fourth component and degree of undercooling.

关键词： Quasicrystal Magnesium alloy Morphology Microhardness

Influence of Allele Frequency on Predicting Animal Phenotype Using Back-Propagation Artificial Neural Networks

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Wuhan University Journal of Natural Sciences 2011年第2期16卷 101-105页

作者： LI Xuebin YU Xiaoling GUO Yunrui XIANG zhifeng zhao Kun REN Fei College of Animal Science Henan Institute of Science andTechnology Xinxiang 453003 Henan China

To overcome the obstacle of the fascinating relation in predicting animal phenotype value, we have developed a neural network model to detect the complex non-linear relationships between the genotypes and phenotypes and the possible interactions that cannot be expressed with equations. In this paper, back-propagation neural network is used to discuss the influences of different allele frequencies on estimating the polygenic phenotype value. To ensure the precision of prediction, normalization was needed to train the prediction model. The results show that back-propagation artificial neural networks can be used to predict the phenotype value and perform very well in allele frequency from 0.2 to 0.8, when the allele frequency is very small （less than 0.2） or big （more than 0.8）; however, the prediction model was not reliable and the predicted value should be carefully tested.

关键词： artificial neural network single-nucleotide polymorphism (SNP) HapMap project genomic breeding value molecular marker allele frequency