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Experimental study on the through-thickness properties of structural steel thick plate and its heat-affected zone at low temperatures

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2015年第3期16卷 217-228页

作者： Yuan-qing WANG Xiao-wei LIAO Yuan-yuan zhang yong-jiu SHI Key laboratory of Civil Engineering Safety and Durability of China Education Ministry Department of Civil Engineering Tsinghua University Beijing 100084 China

Lamellar tearing and crack-induced brittle failures along steel plates in the through-thickness direction seriously threaten the safety and reliability of steel thick plate structures in construction and service, especially at low ambient temperatures. Three kinds of tests, including uniaxial tensile tests, Charpy V-Notch impact tests, and three-point bending （TPB） tests were performed at normal and low temperatures to investigate the through-thickness mechanical properties, impact and fraclure toughness of Q345B structural steel plates with thicknesses from 60 to 165 mm. The test specimens were mainly sampled along the through-thickness direction of the plate, but transverse specimens along the rolling direction were also involved. The ductility index （percentage reduction of area）, impact toughness index （Charpy impact energy）, and fracture toughness index （critical crack tip opening displacement （CTOD） values） all decrease as the temperature declines. All the mechanical properties and the impact and fracture toughness along the through-thickness direction are worse than those along the rolling direction. The results also offer experimental support for the determination of an evaluation indicator for structural steel thick plates with through-thickness characteristics.

关键词： Structural steel thick plate Through-thickness properties Mechanical properties Impact toughness Fracturetoughness Low temperature

A_(2)B_(7)-type La-Mg-Ni alloys prepared by Mg thermal diffusion for improved hydrogen storage performance

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Rare Metals 2024年第7期43卷 3260-3272页

作者： yong-Xi zhang Guan-jiu Wu Jing Gu Hong-Xing Kang Yuan Li Di Zhou Wen-Feng Wang Lu zhang Shu-Min Han Hebei Key Laboratory of Applied Chemistry School of Environmental and Chemical EngineeringYanshan UniversityQinhuangdao 066004China Department of Chemistry and Biochemistry San Diego State UniversitySan DiegoCA92182-1030USA State Key Laboratory of Metastable Materials Science and Technology Yanshan UniversityQinhuangdao 066004China

A novel approach based on thermal diffusion was used to achieve controllable Mg content in A_(2)B_(7)-type La-Mg-Ni-based *** formation mechanism of the A_(2)B_(7)-type phase as a result of the thermal diffusion process and the effect of Mg content on hydrogen storage performance were investigated.X-ray diffraction(XRD)patterns and Rietveld refinement results showed that increased Mg transformed the LaNi_(5)phase in the La_(0.74)Sm_(0.03)Y_(0.23)Ni_(4.32)Al_(0.04)precursor alloy into a superlattice *** electron microscopy(SEM)images showed that Mg was evenly distributed in the alloy *** in the superlattice significantly inhibited the phase decomposition of the superlattice structure during the hydrogen absorption/desorption *** A_(2)B_(7)-type La_(0.57)Sm_(0.02)Y_(0.18)Mg_(0.23)Ni_(3.38)Al_(0.03)alloy composed of Gd_(2)Co_(7)and Ce_(2)Ni_(7)phases was successfully *** pressure-composition isotherm profiles showed that the alloy had a hydrogen storage capacity as high as 1.73 wt%,with good cycling *** 50 cycles of hydrogen absorption/desorption,the alloy retained a hydrogen storage capacity of 1.45 wt%,with a capacity retention rate of up to 84.28%.The Mg thermal diffusion process thus provides a new approach for the controlled preparation of La-Mg-Ni-based alloys.

关键词： La-Mg-Ni-based hydrogen storage alloy A_(2)B_(7)-type superlattice alloy Mg thermal diffusion process Phase transformation Hydrogen storage property

Arbitrary topological charge vortex beams from carbon dots random lasers

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Rare Metals 2024年第8期43卷 3844-3853页

作者： Xiang-Dong Wang Xiao-Bo Mi jiu-Ru He Feng-Ying Ma Jun-Qiao Wang Li Song yong-Qiang zhang Si-Yu Lu yong-Sheng Hu School of Physics and Microelectronics Zhengzhou UniversityZhengzhou 450001China State Key Laboratory of Reliability and Intelligence of Electrical Equipment and Tianjin Key Laboratory of Electronic Materials and Devices School of Electronics and Information EngineeringHebei University of TechnologyTianjin 300401China Green Catalysis Center College of ChemistryZhengzhou UniversityZhengzhou450001China

Vortex beams have attracted great attention due to their promising applications in the fields of high-capacity optical communication,optical micromanipulation,and quantum information ***,we demonstrate vortex beams with flexible control of the topological charge and modes in a carbon dots random laser for the first *** beams with different types,including the Laguerre-Gaussian(LG),Bessel-Gaussian(BG),LG-superposition,and polarized vortex beams with topological charges up to 50,have been successfully ***,vortex beams can be well realized in carbon dots random lasers with different emission wavelengths covering from 465 to 612 *** work would not only enrich the types of vortex laser,especially for solution-processable lasers,but also provide a new route to realizing multicolor and wavelength-tunable vortex lasers.

关键词： Carbon dots Random lasers Vortex beam Topological charge Spatial light modulator

Tectonic Mechanism of the Suining(Ms5.0) Earthquake,Center of Sichuan Basin,China

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Journal of Mountain Science 2013年第1期10卷 84-94页

作者： ZHOU Rong-jun LI yong Laurence SVIRCHEV zhang yong-jiu HE Deng-fa HE Yu-lin ZHAO Pei-lin WANG Zan-jun LONG Feng SU Jin-rong WANG Shi-yuan LIANG Ming-jian LIU Yu-fa KANG Chuan-chuan Earthquake Administration of Sichuan Province National Key Laboratory of Oil and Gas Reservoir Geologyand Exploitation Chengdu University of Technology Royal Roads University School of Peace and Conflict Management China University of Geoscience Earthquake Administration of Chongqing Municipality

On Jan.31 of 2010,the Suining earthquake occurred at Suining City whch is located the center of Sichuan *** is unusual for the strong earthquake to occur at the center of Sichuan Basin with a stable geotectonic environment and a low-level historical *** macro-epicenter of the earthquake is located at Moxi town of Suining city,Sichuan province,*** earthquake intensity of the epicenter area is degree VII,and the long axis of the isoseismal line trends in NE *** Suining earthquake caused the collapse or destruction of 460 family *** earthquake focal mechanism solution and records of the near-field seismographic stations showed the earthquake occurred at the reverse fault at a depth 34 *** on the waveform and focal mechanism,we consider the Suning earthquake is triggered by the reverse fault and not by the gravitational collapse or man-made explosive *** on seismic refraction profile and borehole,we consider that the earthquake is triggered by the backthrust fault of Moxi anticline rooted in detachments at a depth 3-4 ***,we infer that tectonic mechanism of the Suining(Ms5.0) Earthquake is driven by the horizontal crustal shortening and stress adjustment on a shallow detachment after the Wenchuan(Ms 8.0) earthquake.

关键词： Suining(Ms5.0) earthquake Disaster Tectonic mechanism Horizontal crustal shortening Backthrust fault Shallow detachment Sichuan Basin

Elastic three-dimensional phononic topological insulators with Dirac hierarchy

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Science China(Physics,Mechanics & Astronomy) 2024年第5期67卷 54-62页

作者： Shao-yong Huo Qiu-Shuang Yang jiu-jiu Chen Hong-Kang Li Long-Chao Yao Fu-Chun He Chun-Ming Fu College of Mechanical Engineering University of South ChinaHengyang 421001China State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body College of Mechanical and Vehicle EngineeringHunan UniversityChangsha 410082China

Three-dimensional(3D)phononic topological insulators(TIs)featuring two-dimensional(2D)surface states and one-dimensional(1D)hinge states have opened up a new route for multi-dimensional robust wave transport,providing unprecedented methods for integrated acoustic sensors and energy harvesting ***,aiming at the elastic 3D phononic TI with gapless surface states and hinge states,the realization of elastic 3D phononic TIs with gapless surface states and hinge states is a significant challenge due to the complicated multi-mode polarization of elastic waves in 3D *** this study,we demonstrate an elastic 3D phononic TI with a Dirac hierarchy by elaborately operating the corresponding spatial symmetries of the chiral honeycomb ***,a 3D double Dirac cone of elastic wave can be achieved by doubling the lattice along the outof-plane direction to fold two iso-frequency Weyl *** topological phase transitions and 2D gapless two-fold Dirac surface states of elastic wave are realized by breaking the half-lattice spatial translation ***,based on the Brillouin zone folding along the in-plane direction,the 2D gapless two-fold surface Dirac cones are folded into four-fold surface Dirac ***,by inducing the relative radius of adjacent holes to break the in-plane spatial inversion symmetry,the fourfold surface Dirac cones are gapped and associated with a surface state inversion,in which the gapless 1D hinge Dirac dispersion is *** research offers a route for engineering the hierarchies of TIs in 3D elastic wave systems and provides new possibilities for designing 3D ultrasonic devices with unconventional functions.

关键词： Dirac topological hierarchy

Recent advances in multifunctional shape memory photonic crystals and practical applications

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Nano Research 2024年第1期17卷 79-96页

作者： yong Qi Shufen zhang State Key Laboratory of Fine Chemicals Frontier Science Center for Smart MaterialsDalian University of TechnologyDalian 116024China

Shape memory photonic crystals(SMPCs)are smart composite materials with changeable structural color integrated by shape memory polymer and photonic *** can produce one or more temporary shapes through nanoscale deformation,memorizing current *** can be recovered to their original shapes or some intermediate states under external stimuli,accompanied by the variation of structural *** porous carriers with built-in sensing properties,SMPCs promoted the interdisciplinary development of nanophotonic technology in materials science,environmental engineering,biomedicine,chemical engineering,and ***,the recent progress on multifunctional SMPCs and practical applications,including traditional and cold programmable SMPCs,is summarized and *** primary concern is shape programming at the nanoscale that has demonstrated numerous attractive functions,including smart sensing,ink-free printing,solvent detection,reprogrammable gradient wetting,and controllable bubble transportation,under variations of the surface *** aims to figure out the nanoscale shape memory effects on structural color conversion and additional performance,inspiring the fabrication of the next generation of ***,perspectives on future research directions and applications are also *** is believed that multifunctional SMPCs are powerful nanophotonic tools for the interdisciplinary development of numerous disciplines in the future.

关键词： photonic crystal shape memory structural color cold programmable shape recovery

Symmetrization of quasi-regular patterns with periodic tilting of regular polygons

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Computational Visual Media 2024年第3期10卷 559-576页

作者： Zhengzheng Yin Yao Jin Zhijian Fang Yun zhang Huaxiong zhang jiu Zhou Lili He School of Computer Science and Technology Zhejiang Sci-Tech UniversityHangzhou 310018China Zhejiang Provincial Innovation Center of Advanced Textile Technology Shaoxing 312000China School of Media Engineering Communication University of ZhejiangHangzhou 310018China

Computer-generated aesthetic patterns arewidely used as design materials in various fields. Themost common methods use fractals or dynamicalsystems as basic tools to create various patterns. Toenhance aesthetics and controllability, some researchershave introduced symmetric layouts along with thesetools. One popular strategy employs dynamical systemscompatible with symmetries that construct functionswith the desired symmetries. However, these aretypically confined to simple planar symmetries. Theother generates symmetrical patterns under theconstraints of tilings. Although it is slightly moreﬂexible, it is restricted to small ranges of tilingsand lacks textural variations. Thus, we proposed anew approach for generating aesthetic patterns bysymmetrizing quasi-regular patterns using general kuniformtilings. We adopted a unified strategy toconstruct invariant mappings for k-uniform tilings thatcan eliminate texture seams across the tiling ***, we constructed three types of symmetriesassociated with the patterns: dihedral, rotational, andreﬂection symmetries. The proposed method can beeasily implemented using GPU shaders and is highlyefficient and suitable for complicated tiling with regularpolygons. Experiments demonstrated the advantages of our method over state-of-the-art methods in terms ofﬂexibility in controlling the generation of patterns withvarious parameters as well as the diversity of texturesand styles.

关键词： quasi-regular patterns(QRP) k-uniform tilings invariant mappings symmetry aesthetic patterns

Deep learning CNN-APSO-LSSVM hybrid fusion model for feature optimization and gas-bearing prediction

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Petroleum Science 2024年第4期21卷 2329-2344页

作者： jiu-Qiang Yang Nian-Tian Lin Kai zhang Yan Cui Chao Fu Dong zhang College of Earth Sciences and Engineering Shandong University of Science and Technology Laboratory for Marine Mineral Resources Qingdao National Laboratory for Marine Science and Technology Transportation Institute of Inner Mongolia University Key Laboratory of Gas Hydrate Qingdao Institute of Marine Geology Ministry of Natural Resources

Conventional machine learning(CML) methods have been successfully applied for gas reservoir prediction. Their prediction accuracy largely depends on the quality of the sample data; therefore, feature optimization of the input samples is particularly important. Commonly used feature optimization methods increase the interpretability of gas reservoirs; however, their steps are cumbersome, and the selected features cannot sufficiently guide CML models to mine the intrinsic features of sample data efficiently. In contrast to CML methods, deep learning(DL) methods can directly extract the important features of targets from raw data. Therefore, this study proposes a feature optimization and gas-bearing prediction method based on a hybrid fusion model that combines a convolutional neural network(CNN)and an adaptive particle swarm optimization-least squares support vector machine(APSO-LSSVM). This model adopts an end-to-end algorithm structure to directly extract features from sensitive multicomponent seismic attributes, considerably simplifying the feature optimization. A CNN was used for feature optimization to highlight sensitive gas reservoir information. APSO-LSSVM was used to fully learn the relationship between the features extracted by the CNN to obtain the prediction results. The constructed hybrid fusion model improves gas-bearing prediction accuracy through two processes of feature optimization and intelligent prediction, giving full play to the advantages of DL and CML methods. The prediction results obtained are better than those of a single CNN model or APSO-LSSVM model. In the feature optimization process of multicomponent seismic attribute data, CNN has demonstrated better gas reservoir feature extraction capabilities than commonly used attribute optimization methods. In the prediction process, the APSO-LSSVM model can learn the gas reservoir characteristics better than the LSSVM model and has a higher prediction accuracy. The constructed CNN-APSO-LSSVM mode

关键词： Multicomponent seismic data Deep learning Adaptive particle swarm optimization Convolutional neural network Least squares support vector machine Feature optimization Gas-bearing distribution prediction

汶川8.0级地震前紫坪铺库区震源机制及应力场特征

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地震地质 2010年第4期32卷 614-627页

作者：张永久张致伟四川省地震局成都610041

利用2004年8月16日到2008年5月12日汶川8.0级地震前紫坪铺水库数字地震台网和成都数字地震台网的地震波形资料,运用振幅比方法计算了紫坪铺库区486次1.6级以上地震的震源机制参数;根据得到的震源机制参数分析了紫坪铺库区震源机制和应... 详细信息

利用2004年8月16日到2008年5月12日汶川8.0级地震前紫坪铺水库数字地震台网和成都数字地震台网的地震波形资料,运用振幅比方法计算了紫坪铺库区486次1.6级以上地震的震源机制参数;根据得到的震源机制参数分析了紫坪铺库区震源机制和应力场的时空变化特征。结果显示:2006—2008年紫坪铺水库水域范围内逆冲型地震很少,走滑型地震增加;距水域较远的区域逆冲型地震的比例偏高,走滑型地震没有增加;各区域的平均主压应力场的方位在汶川8.0级地震前出现了不同程度的偏转和扰动。

关键词：紫坪铺水库汶川地震震源机制应力场