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Effect of Li content on the microstructure and properties of lead-free piezoelectric(K_(0.5)Na_(0.5))_(1-x)Li_xNbO_3 ceramics prepared by SPS

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Journal of University of Science and Technology Beijing 2008年第3期15卷 314-319页

作者： Pei Zhao Boping zhang Ke Wang Limin zhang hailong zhang School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China

Lead-free piezoelectric （K0.5sNa0.5）1-xLixNbO3 （x = 0at%-20at%） ceramics were synthesized by spark plasma sintering （SPS） at low temperature and the effects of LiNbO3 addition on its crystal structure and properties were also studied. When the Li content was less than 6at%, a single proveskite phase with the similar structure of （K0.5Na0.5）NbO3 was formed; and a secondary phase with K3Li2Nb5O15 structure was observed in the 6at% 〈 x 〈 20at% compositional range. Furthermore, LiNbO3 existed as the third phase when the Li content was higher than 8at%. The grain sizes increased from 200-500 nm to 5-8 μm when the K3Li2Nb5O15 and LiNbO3 like phases were formed. With increasing Li content, the relative density of the ceramics first decreased from 97% to 93% and then kept constant. The piezoelectric coefficient d33, dielectric constant, and planner electromechanical coupling factor exhibited a decreasing tendency with increasing Li content because of the decrease in density and the formation of the secondary phase such as K3Li2Nb5O15 and LiNbO3. The formation of dense microstructure with a single phase is necessary in improving the properties of the （K0.5Na0.5）1-xLixNbO3 ceramics.

关键词： lead-free piezoelectric ceramics spark plasma sintering crystal structure piezoelectric properties

Origins of Terrestrial Organic Matter in Surface Sediments of the East China Sea Shelf

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Journal of Ocean University of China 2017年第5期16卷 793-802页

作者： zhang hailong XING Lei ZHAO Meixun Key Laboratory of Marine Chemistry Theory and Technology(Ocean University of China) Ministry of Education/Qingdao Collaborative Innovation Center of Marine Science and TechnologyQingdao 266100P.R.China Institute of Marine Organic Geochemistry Ocean University of ChinaQingdao 266100P.R.China

Terrestrial organic matter(TOM) is an important component of marine sedimentary OM, and revealing the origins and transport mechanisms of TOM to the East China Sea(ECS) is important for understanding regional carbon cycle. A novel approach combining molecular proxies and compound-specific carbon isotopes is used to quantitatively constrain the origins and transport mechanisms of TOM in surface sediments from the ECS shelf. The content of terrestrial biomarkers of(C_(27)+C_(29)+C_(31)) n-alkanes(52 to 580 ng g^(-1)) revealed a seaward decreasing trend, the δ^(13)CTOC values(-20.6‰ to-22.7‰) were more negative near the coast, and the TMBR(terrestrial and marine biomarker ratio) values(0.06 to 0.40) also revealed a seaward decreasing trend. These proxies all indicated more TOM(up to 48%) deposition in the coastal areas. The Alkane Index, the ratio of C_(29)/(C_(29)+C_(31)) n-alkanes indicated a higher proportion of grass vegetation in the coastal area; While the δ13C values of C_(29) n-alkane(-_(29).3‰ to-33.8‰) indicated that terrestrial plant in the sediments of the ECS shelf were mainly derived from C_3 plants. Cluster analysis afforded detailed estimates of different-sourced TOM contributions and transport mechanisms. TOM in the Zhejiang-Fujian coastal area was mostly delivered by the Changjiang River, and characterized by higher %TOM(up to 48%), higher %C_3 plant OM(68%-85%) and higher grass plant OM(56%-61%); TOM in the mid-shelf area was mostly transported by aerosols, and characterized by low %TOM(less than 17%), slightly lower C_3 plant OM(56%-72%) and lower grass plant OM(49%-55%).

关键词： alkanes coastal terrestrial shelf sedimentary mostly aerosols vegetation quantitatively decreasing

Modeling All-sky Global Solar Radiation Using MODIS Atmospheric Products:A Case Study in Qinghai-Tibet Plateau

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Chinese Geographical Science 2010年第6期20卷 513-521页

作者： zhang hailong LIU Gaohuan HUANG Chong State Key Laboratory of Resources and Environmental Information System Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China

The surface solar radiation(SSR) is of great importance to bio-chemical cycle and life ***,it is impossible to observe SSR directly over large areas especially for rugged surfaces such as the Qinghai-Tibet *** paper presented an improved parameterized model for predicting all-sky global solar radiation on rugged surfaces using Moderate Resolution Imaging Spectroradiometer(MODIS) atmospheric products and Digital Elevation Model(DEM).The global solar radiation was validated using 11 observations within the *** correlation coefficients of daily data vary between 0.67-0.86,while those of the averages of 10-day data are between *** model indicates that the attenuation of SSR is mainly caused by cloud under cloudy sky,and terrain is an important factor influencing SSR over rugged surfaces under clear sky.A positive relationship can also be inferred between the SSR and *** with horizontal surfaces,the south-facing slope receives more radiation,followed by the west-and east-facing slopes with less SSR,and the SSR of the north-facing slope is the least.

关键词： DEM all sky surface solar radiation MODIS Qinghai-Tibet Plateau

The Cognition Is Not Enough:Another Look on Existing Interesting Points Chosen Methods

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Chinese Journal of Electronics 2017年第2期26卷 416-423页

作者： FAN Guangjun ZHOU Yongbin zhang hailong FENG Dengguo State Key Laboratory of Computer Science Institute of SoftwareChinese Academy of Sciences State Key Laboratory of Information Security Institute of Information EngineeringChinese Academy of Sciences

For classical template attacks,many papers suggested a guideline of choosing interesting points which is still not *** to now,many different methods of choosing interesting points were ***,it is still unclear that which approach will lead to the best classification performance for template *** comprehensively evaluate and compare the classification performance of template attacks when using different methods of choosing interesting *** results show that the Correlation power analysis based method and the Sum of squared pairwise t-differences based method will lead to the best classification *** find that some methods of choosing interesting points provide the same results in the same ***,we correctly prove the guideline of choosing interesting points is correct by presenting a new way of conducting template attacks.

关键词： Side-channel attacks Power analysis attacks Template attacks Interesting points

Protective benefit of folded linear HDPE board sand fences along the Golmud-Korla Railway,China:Field observation and wind tunnel study

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Journal of Mountain Science 2024年第7期21卷 2206-2219页

作者： zhang Kai TIAN Jianjin WANG Zhenghui zhang hailong zhang Xingxin College of Civil Engineering Lanzhou Jiaotong UniversityLanzhou 730000China Key Laboratory of Desert and Desertification Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China College of Civil Engineering Chongqing UniversityChongqing 400045China

The Milan Gobi area of the Golmud-Korla Railway in northwest China is located in the lower dispersal area of the mountain pass and has strong winds with evident double wind direction *** study introduced a novel sand fence deployment technique,termed‘folded linear deployment',designed to position the sand fence orthogonally to the two predominant wind directions for optimal *** study used wind tunnel and field tests to evaluate the wind and sand flow characteristics,as well as the windproof and sandresistant performance of folded linear HDPE(Highdensity polyethylene)board sand *** results suggest that the airflow around the fence creates clear zoning *** deceleration area on the BSF(backwind side of the sand fence)is much larger than that on the DSF(downwind side of the sand fence).Thus,sand particles are primarily deposited on the *** different wind speeds,the airflow at 2 and 5 h on the DSF is not *** WSP(wind speed profile)presents a logarithmic *** airflow is disturbed at 1-20 h on the BSF,and the WSP gradually deviates from the logarithmic ***,as the airflow moves away from the fence,the WSP gradually approaches a logarithmic ***,the WPE(windproof efficiency)and SRE(sand-resistant efficiency)of the sand fence exceed 80%.In addition,the results of wind tunnel tests are compared with those of field *** overall dispersion is good,and the best dispersion is found at z/H=2.00,indicating good agreement between the two test *** study provides a scientific basis for the design of sand hazard control measures,similar to the railway project in the Gobi Gale area.

关键词： Folded linear HDPE board sand fence Double wind direction Gobi area Protection benefit

Resource allocation for load balancing and fairness improvement in relay-assisted OFDMA cellular

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High Technology Letters 2011年第4期17卷 377-382页

作者： zhang hailong Ji Hong Li Xi Key Lab of Universal Wireless Communications Ministry of EducationBeijing University of Posts and Telecommunications Beijing 100876 P.R.China

A resource allocation scheme with the considerations of user fairness and load balancing is proposed in orthogonal frequency division multiple access （OFDMA）-based relay networks. The optimal resource allocation scheme is formulated mathematically to maximize the minimum achievable rate among all user equipments （UEs） for fairnegs improvement. The optimal problem has been proved to be N-P-hard and it is prohibitive to find the optimal solution for its computational complexity. Accordingly, this paper proposes a suboptimal scheme which considers not only user fairness but also load balancing among base stations （BS） and relay stations （RSs） during resource allocation procedure. The suboptimal scheme takes the traffic load of access nodes （BS and RSs） into consideration to balance the system traffic load, which would prevent them from overloading and throughput degradation. Simulation results show that the suboptimal scheme performs similarly to the optimal solution and can enhance the system fairness and load balancing performance significantly compared with the traditional schemes.

关键词： radio resource allocation relay fairness load balancing orthogonal frequency division multiple access (OFDMA)

Semi-active Sliding Mode Control of Vehicle Suspension with Magneto-rheological Damper

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Chinese Journal of Mechanical Engineering 2015年第1期28卷 63-75页

作者： zhang hailong WANG Enrong zhang Ning MIN Fuhong SUBASH Rakheja SU Chunyi School of Physics and Technology Nanjing Normal University School of Electric and Automation Engineering Nanjing Normal University Department of Mechanical Engineering Concordia University

The vehicle semi-active suspension with magneto-theological damper（MRD） has been a hot topic since this decade, in which the robust control synthesis considering load variation is a challenging task. In this paper, a new semi-active controller based upon the inverse model and sliding mode control （SMC） strategies is proposed for the quarter-vehicle suspension with the magneto-rheological （MR） damper, wherein an ideal skyhook suspension is employed as the control reference model and the vehicle sprung mass is considered as an uncertain parameter. According to the asymptotical stability of SMC, the dynamic errors between the plant and reference systems are used to derive the control damping force acquired by the MR quarter-vehicle suspension system. The proposed modified Bouc-wen hysteretic force-velocity （F-v） model and its inverse model of MR damper, as well as the proposed continuous modulation （CM） filtering algorithm without phase shift are employed to convert the control damping force into the direct drive current of the MR damper. Moreover, the proposed semi-active sliding mode controller （SSMC）-based MR quarter-vehicle suspension is systematically evaluated through comparing the time and frequency domain responses of the sprung and unsprung mass displacement accelerations, suspension travel and the tire dynamic force with those of the passive quarter-vehicle suspension, under three kinds of varied amplitude harmonic, rounded pulse and real-road measured random excitations. The evaluation results illustrate that the proposed SSMC can greatly suppress the vehicle suspension vibration due to uncertainty of the load, and thus improve the ride comfort and handling safety. The study establishes a solid theoretical foundation as the universal control scheme for the adaptive semi-active control of the MR full-vehicle suspension decoupled into four MR quarter-vehicle sub-suspension systems.

关键词： magneto-rheological damper vehicle suspension multi-objective performance semi-active sliding mode control filtering

Numerical simulation on sand sedimentation and erosion characteristics around HDPE sheet sand barrier under different wind angles

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Journal of Mountain Science 2024年第2期21卷 538-554页

作者： zhang Kai zhang Peili zhang hailong TIAN Jianjin WANG Zhenghui XIAO Jianhua College of Civil Engineering Lanzhou Jiaotong UniversityLanzhou 730000China Key Laboratory of Desert and Desertification Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China Key Laboratory of Ecological Safety and Sustainable Development in Arid Lands Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China

For the safety of railroad operations,sand barriers are utilized to mitigate wind-sand disaster *** disasters,characterized by multi-directional wind patterns,result in diverse angles among the *** this study,using numerical simulations,we examined the behavior of High Density Polyethylene(HDPE)sheet sand barriers under different wind angles,focusing on flow field distribution,windproof efficiency,and sedimentation erosion *** study discovered that at a steady wind speed,airflow velocity varies as the angle between the airflow and the HDPE barrier ***,a 90°angle results in the widest low-speed airflow area on the barrier’s downwind *** the airflow is not perpendicular to the barrier,it prompts a lateral airflow movement which decreases as the angle *** windproof efficiency correlates directly with this angle but inversely with the wind’s ***,with a wind angle of 90°,wind speed drops by 81%.The minimum wind speed is found at 5.1H(the sand barrier height)on the barrier’s downwind *** the angle grows,the barrier’s windproof efficiency improves,extending its protective *** is most prominent on the barrier’s downwind side,as the wind angle shifts from 30°to 90°,the sand sedimentation area on the barrier’s downwind side enlarges by *** the angle grows,sedimentation intensifies,eventually overtakes the forward erosion and enlarges the sedimentation area.

关键词： Multi-wind direction HDPE sheet sand barrier Numerical simulation Windproof efficiency Sedimentation erosion

A Novel S-Box GenerationMethodology Based on the Optimized GANModel

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Computers, Materials & Continua 2023年第8期76卷 1911-1927页

作者： Runlian zhang Rui Shu Yongzhuang Wei hailong zhang Xiaonian Wu Guangxi Key Laboratory of Cryptography and Information Security Guilin University of Electronic TechnologyGuilin541004China State Key Laboratory of Information Security Institute of Information EngineeringChinese Academy of SciencesBeijing100085China

S-boxes can be the core component of block ciphers,and how to efficiently generate S-boxes with strong cryptographic properties appears to be an important task in the design of block *** this work,an optimized model based on the generative adversarial network(GAN)is proposed to generate 8-bit *** central idea of this optimized model is to use loss function constraints for *** specially,the Advanced Encryption Standard(AES)S-box is used to construct the sample dataset via the affine equivalence ***,three models are respectively built and cross-trained to generate 8-bit S-boxes based on three extended frameworks of GAN,i.e.,Deep Convolution Generative Adversarial Networks(DCGAN),Wasserstein Generative Adversarial Networks(WGAN),and WassersteinGenerativeAdversarial NetworkwithGradient Penalty(WGANGP).Besides,an optimized model based onWGAN-GP referred to asWGPIM is also proposed,which adds the loss function constraints to the generator network of the WGAN-GP model,including bijection loss,differential uniformity loss,and nonlinearity *** this case,8-bit S-boxes can be generated with *** results illustrate that the WGP-IM model can generate S-boxes with excellent cryptographic *** particular,the optimal differential uniformity of the generated S-boxes can be reduced to 8,and the nonlinearity can be up to *** with previous S-box generation methods,this new method is simpler and it can generate S-boxes with excellent cryptographic properties.

关键词： S-box generative adversarial network loss function affine equivalence