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Abstract Semiconductors are an important electronic component and play a central role in many industrial fields, whose production system is spread all over the world, involving trade in many raw materials, mechanical equipment, and finished products. Comprehending a broad global production picture of the semiconductor industry can be an arduous task. To tackle this complexity, the social network analysis method was used to capture the flows of products between economies in the semiconductor industrial chain. This study analyzed the evolution of the trade pattern of four key commodities in the semiconductor industrial chain, with a focus on identifying the status of major economies in the global semiconductor trade system. Additionally, the influencing factors of the formation of the trade networks were explored by using the Exponential Random Graph Model. The results showed that: (1) From 2001 to 2019, the import and export trade pattern of four key commodities in the semiconductor industrial chain has shown the characteristics of “rising in the east and decreasing in the west”, but the change range shows strong commodity heterogeneity, the change of the spatial pattern of integrated circuits trade is the most significant, and the integrated circuits trade proportion of Asian economies has increased hugely with more than 80%. (2) The trade connectivity of various commodities in the semiconductor industrial chain has increased, upstream support products with high technical requirements such as wafers and equipment have the lowest average degree and weak trade liquidity, and the average degree of trade network of packaging materials and integrated circuits is relatively high, with strong trade liquidity and closer and more prosperous trade connections. (3) From 2001 to 2019, the “core-periphery” system of global semiconductor industry trade has changed significantly, with the core circle undergoing obvious iterative reorganization. for example, China and Singapore have achieved status improvement to the core circle in the base materials trade network, while Malaysia has been squeezed into the semi-peripheral circle. (4) The formation of trade networks of various commodities in the semiconductor industrial chain was driven by three aspects: network self-organization, exogenous endowment attribute, and exogenous network embeddedness. Among them, the influence of the technological innovation level of economies on different commodity trade networks showed heterogeneous.

Wind velocity is usually assumed to obey a stationary stochastic process in wind engineering, and this may cause significant bias in describing extremely severe strong wind such as typhoons and thunderstorms. To take into account the non-stationary characteristics of extreme wind, a novel evolutionary power spectral density (EPSD) model is proposed, and the spectral representation method (SRM) is introduced to simulate the whole process of strong winds. Firstly, the wavelet transform (WT) method is adopted to capture the three-dimensional time-varying properties of the low-frequency mean winds, and the associated turbulence features, including turbulent intensity, gust factor, probability density function, and power spectrum, are analyzed in depth. Secondly, the measured horizontal EPSD of strong winds are estimated. Thirdly, the performance of the proposed EPSD model is validated. Finally, the whole process of non-stationary strong winds are simulated and discussed. The results show that the proposed EPSD models are in good agreement with the measured EPSD, and the time-frequency features of the power spectrum of the simulated winds are well reproduced, which provides a powerful tool for large eddy simulation and wind engineering studies under non-stationary extreme wind climate.

As the lightest metal structural materials, Mg alloys have great application potential in transportation, aerospace, and biomedicine. However, the further application is hindered by their low strength, plasticity, and poor corrosion resistance. The preparation of Mg alloys with ultra-fine grain (UFG) structure is regarded as a good solution to improve their performance, and has been reported by a large number of literatures. The purpose of this paper is to summarize the development of fabrication processes of UFG Mg alloys and the effects of UFG structure on the mechanical properties and corrosion resistance. In essence, this review aims to elucidate the evolution and current state of UFG structure in Mg alloys. Additionally, it seeks to expound upon the strategies for designing and preparing these structures and shed light on the future development trends. The ultimate goal is to advance the utilization of UFG Mg alloys in both structural and functional materials.

This study presents a novel technology in the fabrication of AZ31 Mg alloy sheets using continuous shear extrusion (CSE) with multiple shear platforms at 340 °C. Compared with the conventional extrusion (CE), an asymmetric shear deformation was introduced so that the basal texture deflects towards to extrusion direction. Through finite element simulation, it was found that the differences in flow velocity and strain distributions along the thickness direction can be achieved by introducing the shear strain through CSE technology. Finer grains and more uniform microstructure were obtained in CSEed Mg samples compared to conventional extrusion. The average grain size decreased from 6.33 μm in CE samples to 3.94 μm in CSE samples, and 3.39 μm in CSE-II samples. The continuous asymmetric shear force also led to the basal plane inclining approximately 15° towards the extrusion direction, leading to a weakening of basal texture intensity. In terms of mechanical properties, the CSE Mg plates exhibited higher yield strength (YS), ultimate tensile strength (UTS), and fracture elongation (FE) along the extrusion direction. These improvements in mechanical performance can be attributed to enhanced work hardening ability, texture weakening, finer grains generation, and the dislocation strengthening induced by shear strain.

The effects of small additions of calcium (0.1% and 0.5%11 All compositions in weight percentage.) on the dynamic recrystallization behavior and mechanical properties of as-extruded Mg-1Mn-0.5Al alloys were investigated. Calcium microalloying led to the formation of Al2Ca in as-cast Mg-1Mn-0.5Al-0.1Ca alloy and both Mg2Ca and Al2Ca phases in Mg-1Mn-0.5Al-0.5Ca alloy. The formed Al2Ca particles were fractured during extrusion process and distributed at grain boundary along extrusion direction (ED). The Mg2Ca phase was dynamically precipitated during extrusion process, hindering dislocation movement and reducing dislocation accumulation in low angle grain boundaries (LAGBs) and hindering the transformation of high density of LAGBs into high angle grain boundaries (HAGBs). Therefore, a bimodal structure composed of fine dynamically recrystallized (DRXed) grains and coarse unDRXed regions was formed in Ca-microalloyed Mg-1Mn-0.5Al alloys. The bimodal structure resulted in effective hetero-deformation-induced (HDI) strengthening. Additionally, the fine grains in DRXed regions and the coarse grains in unDRXed regions and the dynamically precipitated Mg2Ca phase significantly enhanced the tensile yield strength from 224 MPa in Mg-1Mn-0.5Al to 335 MPa and 352 MPa in Mg-1Mn-0.5Al-0.1Ca and Mg-1Mn-0.5Al-0.5Ca, respectively. Finally, a yield point phenomenon was observed in as-extruded Mg-1Mn-0.5Al-xCa alloys, more profound with 0.5% Ca addition, which was due to the formation of (101¯2)extension twins in unDRXed regions.

Transverse gradient extrusion (TGE) processes with different die inclined angles of 15°, 30°, 45°and 60° were used to produce Mg–3Al–1Zn sheets, thereby tailoring texture and mechanical properties of Mg alloy sheets. Microstructure, deformation texture and final mechanical properties of the obtained sheets were detected and discussed. Furthermore, the rheological behavior of Mg alloys during extrusion was analyzed by finite element method. As the TGE die inclined angle changed, the flow velocity along the transverse direction (TD) and effective strain difference along extrusion direction (ED) were changed during extrusion, and therefore the microstructure and texture of extruded sheets are altered. With increase of TGE die inclined angles, fine grain size and uniform microstructure were obtained. The base poles of most grains for the extruded sheets gradually deviate from normal direction (ND) to ED at center region and inclined from ED to TD at 1/4 edge region. A large elongation of 33.9 % and a low yield stress of 125 MPa can be obtained in the TGE-45 sheet.

Downbursts belong to sudden, local, and strong convection weather, which present significant destruction for structures. At any given time, there are approximately 2000 thunderstorms occurring on the Earth. Many studies have investigated the effects of downbursts on different structures. However, the extensive range of varying wind field parameters and the diverse representations of wind speeds render the study of structural wind effects complex and challenging under downbursts. This study firstly reviews the research of wind field properties of downbursts according to four common approaches, and the major findings, advantages, and disadvantages of which are concluded. Then, failure analysis of transmission line systems under stationary and moving downbursts is explored. The article also reviews the wind pressure on the roof of different kinds of low-rise buildings, and some dominant parameters, namely roof slope, distance of building from downburst center, wind direction angle, and so on, are discussed. Moreover, the wind effects caused by downbursts on high-rise buildings and some specialized structures are also considered because more and more wind hazards are related to downbursts. Finally, the limitations of the current study are pointed out, and recommendations for further research are given for the accurate assessment of the effects of wind on buildings, with a view to providing safer and more economical wind-resistant design solutions for structures.

The distribution of vegetation in coastal wetlands is significantly influenced by soil properties. However, the mechanisms of how soil characteristics impact the physiological processes of Tamarix chinensis forests remain underexplored. This study examined changes in the soil physicochemical properties and structural attributes of natural T. chinensis forests in the Yellow River Delta with increasing distance from the shoreline. T. chinensis trees were classified into healthy, intermediate, and dying categories based on growth potential, and dynamic changes in salt ions and non-structural carbohydrates (NSCs) were investigated. Results indicated that increasing distance from the shoreline corresponded to decreased soil salinity and pH, and increased soil moisture. T. chinensis mortality rate decreased, while tree height and ground diameter increased with distance. Soil salt content was positively correlated with T. chinensis mortality, but negatively correlated with tree height and ground diameter. Trees with lower growth potential had higher Na+ but lower K+ and K+/Na+ ratio. Soil salt content was positively correlated with root and stem Na+, while soil moisture was positively correlated with leaf NSCs. These findings suggest that soil salt content and moisture significantly influence T. chinensis ion absorption and NSC accumulation, with sodium toxicity being a key factor in the spatial distribution of T. chinensis forests.

In order to further improve the comprehensive mechanical properties of commercial AZ31 Mg alloy, AZ31/graphene nano particulates (GNP) composites were prepared by AZ31 Mg alloy and graphene through friction stir processing (FSP) and following rolling. The microstructure and mechanical properties of as-FSPed and as-rolled alloys were investigated in this study. Compared with base metal, the ductility of FSPed alloys is greatly increased, while the strength is somewhat decreased. After further rolling on the FSPed plate, the strength of the alloy is improved. AZ31/GNP composites processed by FSP and rolling (50% reduction ratio) exhibits excellent mechanical properties with ultimate tensile strength of 296 MPa and elongation of 15.7%. The improved performance is attributed to the refinement of the grain and the homogenization of the second phase, which are the result of the severe plastic deformation characteristics of FSP. The multiplication of dislocations originated from rolling deformation and the reinforcement of GNP also contribute to the strength. The results verify that FSP as an intermediate step before rolling can be used as an effective mean to add reinforcement particles. On the other hand, the improved microstructure induced by severe plastic deformation of FSP is beneficial for further rolling.

Glioblastoma stem-like cells (GSCs) contribute to therapeutic resistance and recurrence of glioblastomas. Here the authors show that Insulin-like Growth Factor-Binding Protein 5 (IGFBP5) is a ligand for Receptor tyrosine kinase-like Orphan Receptor 1 (ROR1) promotes GSCs invasion.

In this study, the microstructure and mechanical properties of the commercial magnesium (Mg) ZK60 alloy were conducted to promote the application of Mg alloys. Scanning electron microscopy, tensile and compression tests, electron back scattering diffraction, transmission electron microscope and visco-plasticity self-consistent methods were employed to analyze the microstructure evolution and the strengthening and toughening mechanisms. By direct extrusion in the as-cast state, a bimodal microstructure was obtained, and the mechanical properties were enhanced. The ZK60 alloy, with a bimodal grain structure, exhibited a good combination of strength and ductility. The tensile yield strength (TYS), ultimate tensile strength (UTS), compressive yield strength (CYS) and fracture elongation (FE) reached 272 MPa, 347 MPa, 289 MPa, and 36.2%, respectively. Compared with the traditional extrusion ZK60 alloy, the increment in TYS, UTS, CYS, and FE was 15 MPa, 31 MPa, 25 MPa and 8.6%, respectively. The formation of the bimodal structure in the ZK60-CE sample is attributed to the combination of the PSN and Zener pinning effects. The improvement in strength is mainly attributed to the residual dislocations in the un-DRXed grains and the good ductility is ascribed to the activation of the non-basal slip. This study provides a low-cost and efficient strategy for the preparation of the bimodal structure by regulating the pre-extrusion microstructure to improve mechanical properties.

Accurate prediction of wind speed and its output power is playing an essential role in the planning and scheduling of wind power grid. This study presents a novel two-stage data-driven model for ultra-short-term wind speed prediction based on the smoothing spline preprocessing (SSP) method and error optimization theory (EOT). Firstly, high-resolution wind data observed from 39 wind turbines are collected and transformed according to the proposed SSP method to eliminate the non-Gaussian and non-stationary features. Then, several individual models are introduced to perform multi-step ahead wind speed prediction for the transformed wind data, and the prediction of transformed data should be recovered to wind speed. Finally, these single models are combined based on the proposed EOT theory for multi-step ahead wind speed prediction, and their accuracy and uncertainty are analyzed and compared with other existing models in depth. The results show that the proposed SSP method can reasonably identify non-Gaussian and non-stationary features of the original wind series, and the transformed data are more favorable for prediction. Furthermore, the suggested two-stage data-driven model can reduce prediction errors by 3%–20% compared with other models mentioned in this study, indicating that it is more effective and stable in terms of providing reasonable ultra-short-term wind speed prediction results.

As the most successful new energy storage device developed in recent decades, lithium-ion batteries (LIBs) are ubiquitous in the modern society. However, current commercial LIBs comprising mainly intercalated cathode materials are limited by the theoretical energy density which cannot meet the high storing energy demanded by renewable applications. Compared to intercalation-type cathode materials, low-cost conversion-type cathode materials with a high theoretical specific capacity are expected to boost the overall energy of LIBs. Among the different conversion cathode materials, metal fluorides have become a popular research subject for their environmental friendliness, low toxicity, wide voltage range, and high theoretical specific capacity. In this review, we compare the energy storage performance of intercalation and conversion cathode materials based on thermodynamic calculation and summarize the main challenges. The common conversion-type cathode materials are described and their respective reaction mechanisms are discussed. In particular, the structural flaws and corresponding solutions and strategies are described. Finally, we discussed the prospective of metal fluorides and other conversion cathode materials to guide further research in this important field.

Temozolomide (TMZ) is a clinically approved drug for glioblastoma (GBM) therapy. However, as a result of methylguanine-DNA-methyltransferase (MGMT), which is able to repair damaged DNA-damage repairing, TMZ usually yields unsatisfactory therapeutic effects. Small interfering RNA (siRNA) is a potential alteration tool for sensitivity of TMZ by targeting DNA repair enzymes. However, a suitable TMZ and siRNA codelivery system that can effectively and actively co-deliver siRNA/TMZ into the brain tumor is lacking. In this study, we constructed an angiopep-2 decorated polymersomal delivery system to co-deliver TMZ/siRNA for synergistic GBM therapy. This targeted polymersomal nanomedicine not only enhanced the circulation time of siRNA/TMZ in blood but also improved their blood-brain barrier (BBB) crossing and GBM targeting ability. Moreover, when we co-administered siRNAs specific to retinoblastoma binding protein 4 (RBBP4) together with TMZ in GBM cells, these RBBP4-specific siRNA (siRBBP4) modulated the sensitivity of TMZ by regulating MGMT, and thus showed a powerful synergistic anti-tumor effect. We demonstrated that angiopep-2 decorated polymersomal siRBBP4/TMZ co-loaded nanomedicines are capable of inhibiting tumor growth and significantly improved life expectancy of orthotropic GBM bearing mice. Overall, our study suggests that such a polymersomal TMZ/siRNA codelivery system provides a robust and potent nanoplatform for targeted GBM chemo-RNAi therapy.

Population shrinkage has had a certain negative impact on urban and rural development in many aspects. The impact of population shrinkage on urban–rural integration has become one of the core scientific issues that needs to be addressed in the current research on promoting the goal of common prosperity in China. Northeast China is a typical region in China that is experiencing a decrease in population and economic activity. Investigating the integrated development of urban and rural areas in this region is highly important for revitalizing Northeast China. This research paper focuses on 32 prefecture-level cities in Northeast China and utilizes spatial correlation analysis and the Geographical Weighted Regression model to uncover the evolving spatial patterns and influential factors affecting integrated urban–rural development in the context of population decline. The findings revealed the following: (1) The level of integrated urban–rural development in Northeast China continues to rise despite the shrinking population. During the comprehensive population decline stage, the growth rate of the urban–rural coupling coordination degree surpasses that of the initial stage. The areas with high values of urban–rural coupling coordination degree shift from northeastern Heilongjiang to four sub-provincial cities. The spatial correlation between urban–rural coupling and coordinated development weakens, with the main type being low–low agglomeration. (2) Factors such as economic development level, labor force size, urbanization level, level of openness, urban–rural accessibility, and proportion of built-up areas significantly correlate with urban–rural coupling and coordination. The influence of each factor varies in magnitude and direction across different locations. Labor force size and urban–rural accessibility have the most-significant impact on integrated urban–rural development, with labor force size having a positive effect and urban–rural accessibility having a negative effect. The impact of the economic development level follows a pattern of initial increase and subsequent decrease as the population shrinks. (3) Although population decline does not hinder integrated urban–rural development in Northeast China, it is closely connected to changes in the factors influencing such development. To capitalize on the development opportunities presented by national policies, Northeast China should adopt a model of urban–rural development that promotes rural growth through cities. This entails attracting talented individuals to return, enhancing the flow of urban–rural development elements in both directions, and creating a spatial development pattern characterized by “big city, big agriculture, and big ecosystem”. By doing so, the revitalization of Northeast China can be achieved.

A downburst is a typical local highly intensive wind all over the world, which is attributed to be the main cause of wind damage to transmission lines in inland areas worldwide. The collapse accidents of transmission towers under the downburst still occur every year. Therefore, it is of great significance to assess the safety of the transmission towers under downbursts. The motivation of the present study is to propose a fragility assessment method for transmission towers under the action of a downburst considering the uncertainty of wind-resistance capacity and the stochastic wind load effect. First, the downburst wind field of the transmission tower with different wind attack angles and different radial distances is simulated according to the mixed stochastic model. Then, random material characteristic samples are generated by the Latin hypercube sampling technique and applied to establish uncertain finite element models for transmission towers. Next, the static nonlinear buckling analysis is carried out by numerical methods to determine the ultimate capacity under the downburst wind load. The parameter analysis of different wind attack angles and radial distances between the downburst and the tower is conducted to determine the most unfavorable location of the maximum response. The failure mode of the transmission tower and the probabilities of the initial failure main members are summarized. Finally, the fragility curves of the transmission tower under the downburst and the atmospheric boundary layer (ABL) wind are compared. The results show that the maximum response is located at R = 1.6D. Most of the initial buckling members are located close to the first section of the tower. The fragility curves of the tower under the downburst are more dangerous than the ABL wind with the attack angle increasing from 0° to 90°. Furthermore, considering the probability model of intensity and direction of the downburst and based on the previous fragility analysis, the collapse probability of the transmission tower caused by the downburst is obtained. By probability analysis of the parameters, including layout conditions, different directions, and different wind speeds, it is found that the most favorable arrangement is 157.5°, and the most unfavorable arrangement is 112.5°.

The low microalloying content and high yield strength of 365 MPa have been achieved simultaneously in extruded Mg–Ce–Al alloy which is mainly ascribed to the unexpected grain refinement (mean size of ∼420 nm). It is found that adding tiny Al (0.05 wt.%) into Mg–0.2 wt.% Ce alloy can promote the formation of Ce–Al-enriched segregation along dislocations and grain boundaries which can effectively counterbalance the thermally activated dislocation recovery and thus guarantee grain refinement. The ultra-fined grains are mainly related to both linear and planar cosegregation of solutes, rather than the traditional planar segregations and/or nanoprecipitations at grain boundaries.

The AlkB homologs (ALKBH) gene family regulates N6-methyladenosine (m6A) RNA methylation and is involved in plant growth and the abiotic stress response. Poplar is an important model plant for studying perennial woody plants. Poplars typically have a long juvenile period of 7–10 years, requiring long periods of time for studies of flowering or mature wood properties. Consequently, functional studies of the ALKBH genes in Populus species have been limited. Based on AtALKBHs sequence similarity with Arabidopsis thaliana, 23 PagALKBHs were identified in the genome of the poplar 84K hybrid genotype (P. alba × P. tremula var. glandulosa), and gene structures and conserved domains were confirmed between homologs. The PagALKBH proteins were classified into six groups based on conserved sequence compared with human, Arabidopsis, maize, rice, wheat, tomato, barley, and grape. All homologs of PagALKBHs were tissue-specific; most were highly expressed in leaves. ALKBH9B and ALKBH10B are m6A demethylases and overexpression of their homologs PagALKBH9B and PagALKBH10B reduced m6A RNA methylation in transgenic lines. The number of adventitious roots and the biomass accumulation of transgenic lines decreased compared with WT. Therefore, PagALKBH9B and PagALKBH10B mediate m6A RNA demethylation and play a regulatory role in poplar growth and development. Overexpression of PagALKBH9B and PagALKBH10B can reduce the accumulation of H2O2 and oxidative damage by increasing the activities of SOD, POD, and CAT, and enhancing protection for Chl a/b, thereby increasing the salt tolerance of transgenic lines. However, overexpression lines were more sensitive to drought stress due to reduced proline content. This research revealed comprehensive information about the PagALKBH gene family and their roles in growth and development and responsing to salt stress of poplar.

Owing to the hexagonal close-packed (HCP) crystal structure of magnesium alloys, they are characterized by poor plasticity at low temperatures (below recrystallization temperature), which limits their application. Texture control has been proven to be an effective way to enhance the ductility, formability, processability, and so on. Various technologies, which can be classified as alloying elements, induced shear deformation, pre-twins, and recrystallization, have been developed to modify the basal texture. Based on these results, the general mechanisms of texture control in various recent methods are summarized. In addition, applications of Mg products via texture weakening below recrystallization temperatures are also reviewed. Finally, the current problems and the potential research directions on texture control are suggested.

In this work, the effect of thermomechanical processing schedules on microstructure, texture and mechanical anisotropy of Mg-1.64Al-0.84Zn-0.38Mn-0.49Ca (AZMX1100, wt.%) alloy was investigated. Two hot rolling regimes: unidirectional and cross rolling (UR and CR, respectively), followed by subsequent annealing, were systematically studied using different reductions per pass (r. p. p.) from 10 to 30%. The findings showed that the CR samples developed more recrystallized grains and fine twins compared to the UR ones. At a low r. p. p. of 10%, the CR sample exhibited a close circular ring texture. With increasing the r. p. p., an elliptical ring texture along the rolling direction (RD) was observed. For the UR samples, the degree of transverse direction (TD)-split texture component was ascending as the r. p. p. increased. After annealing, the CR annealed samples inherited and expanded texture traits of the as-rolled samples. The UR samples after annealing showed stronger TD-oriented texture components and weakened RD-oriented components. The texture of the UR annealed samples gave rise to a continuous worsening of mechanical anisotropy as the r. p. p. increased. On the contrary, with the r. p. p. of 10%, the CR annealed sample emerged with near isotropic mechanical properties due to the symmetric texture. At the higher r. p. p., the mechanical anisotropy of the CR annealed samples was slightly deteriorated.

In this article, the stability of twins, especially {10–12} twins, in Mg alloys was critically reviewed. In the last decade, pre-twinning is considered to be an effective method for adjusting the microstructure and properties of wrought Mg alloys. Especially, formation of twin-texture can remarkably improve formability of rolled Mg alloys. However, the stability of {10–12} twins determines the effect of this method. Previous work revealed that initial {10–12} twins may either grow or shrink under further deformation, and may be removed by static recrystallization under thermal effect. It is considered that improving the stability of twin structure could enhance the contribution of twin-texture on subsequent plastic formability. Based on this background, stress stability and thermal stability of {10–12} twin structure were summarized and reviewed in this article. Finally, a few critical scientific problems in this research field were pointed out. Keywords: Mg alloys, Twin structure, Stability, Texture, Recrystallization

Abstract Background Clinopodium gracile (Benth.) Matsum (C. gracile) is an annual herb with pharmacological properties effective in the treatment of various diseases, including hepatic carcinoma. Triterpenoid saponins are crucial bioactive compounds in C. gracile. However, the molecular understanding of the triterpenoid saponin biosynthesis pathway remains unclear. Results In this study, we performed RNA sequencing (RNA-Seq) analysis of the flowers, leaves, roots, and stems of C. gracile plants using the BGISEQ-500 platform. The assembly of transcripts from all four types of tissues generated 128,856 unigenes, of which 99,020 were mapped to several public databases for functional annotation. Differentially expressed genes (DEGs) were identified via the comparison of gene expression levels between leaves and other tissues (flowers, roots, and stems). Multiple genes encoding pivotal enzymes, such as squalene synthase (SS), or transcription factors (TFs) related to triterpenoid saponin biosynthesis were identified and further analyzed. The expression levels of unigenes encoding important enzymes were verified by quantitative real-time PCR (qRT-PCR). Different chemical constituents of triterpenoid saponins were identified by Ultra-Performance Liquid Chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC/Q-TOF-MS). Conclusions Our results greatly extend the public transcriptome dataset of C. gracile and provide valuable information for the identification of candidate genes involved in the biosynthesis of triterpenoid saponins and other important secondary metabolites.

Frequency analysis of tornadoes is very important for risk analysis and disaster control. In this paper, the annual frequency of tornadoes that occurred in the United States from 1967 to 2016 is analyzed. The simple analysis shows that frequencies of tornadoes of different sites are spatially correlated and over-dispersed. To explain the two characteristics of the data, the Bayesian hierarchical model is proposed. For comparison purposes, the Bayesian model with negative binomial distribution, Poisson distribution, Polya distribution, and first-order, non-negative, integer-valued autoregressive model with Bell innovations(BL-INAR(1)) are considered to fit the frequency of tornado. The distribution parameters of all sites are assumed to be spatially correlated, and the corresponding Bayesian hierarchical models were established. MCMC (Markov Chain Monte Carlo) method is applied to parameter estimations and relative statistical inference. By comparison of the analysis results, the negative binomial distribution is recommended to analyze the overdispersion and spatial correlation among the sites of the data. The comparison between the simulated frequencies based on the proposed model and the actual frequencies also verifies that the proposed method is a better model for the data.

High-purity titanium has been subjected to dynamic compression with a strain rate of 103 s−1 to activate {112-2} and {112-4} contraction twins. Electron backscatter diffraction (EBSD), transmission electron microscopy (TEM), and high-resolution TEM (HRTEM) were performed to observe the morphologies and twin boundaries of the contraction twins. The results show that {112-2} twins are the predominant twinning mode, as well as the formation of {112-4} twins due to the change in local stress state at the intersection region of {112-2} twin variants or {112-2} twin and grain boundary. The TEM and HRTEM observations reveal that (0001)‖(1122-) facets and (0001)‖(1121-) facets formed along the {112-2} and {112-4} twin boundaries, respectively. According to the theory of interfacial defects, the propagation of the {112-2} twin boundary was discussed with (b3, 3h{112-2}) and (b1, h{112-2}) twinning disconnections, as well as the growth process of the {112-4} twin boundary.

The assessment of extreme wind loading on solar arrays plays a significant role in ensuring their safe operation under strong winds. Therefore, this paper investigates the extreme wind loading on solar arrays mounted on a flat roof by taking into account the wind directionality effect. The estimation process is conducted by using in situ wind speeds obtained from meteorological stations and wind loading coefficients on solar arrays obtained from wind tunnel tests based on the joint probability distribution of multiple variables and their conditional probabilities. This allows a discussion regarding how the extreme wind loading of solar arrays would be affected by such factors as the uncertainty of wind loading coefficient, the structural orientation of buildings on which solar arrays are mounted, and the directional characteristics of wind speeds. Finally, a comparison among the proposed methods, considering the wind directionality in current wind loading codes, is performed. The extreme wind loading determined by multivariate extreme value theory is found to be comparable to the corresponding estimate calculated according to the independent assumption of directional extreme wind speed. The results of this study provide a valuable reference for the design of wind-resistant solar arrays that takes account of wind directionality effect.

Despite all sorts of innovations in medical researches over the past decades, cancer remains a major threat to human health. Mitochondria are essential organelles in eukaryotic cells, and their dysfunctions contribute to numerous diseases including cancers. Mitochondria-targeted cancer therapy, which specifically delivers drugs into the mitochondria, is a promising strategy for enhancing anticancer treatment efficiency. However, owing to their special double-layered membrane system and highly negative potentials, mitochondria remain a challenging target for therapeutic agents to reach and access. Polymeric nanoparticles exceed in cancer therapy ascribed to their unique features including ideal biocompatibility, readily design and synthesis, as well as flexible ligand decoration. Significant efforts have been put forward to develop mitochondria-targeted polymeric nanoparticles. In this review, we focused on the smart design of polymeric nanosystems for mitochondria targeting and summarized the current applications in improving cancer therapy.

This paper investigates the twisted wind effect on a typical super-tall building (500-m-tall square prism) by conducting pressure model wind tunnel tests. Two twisted wind fields (TWFs) with maximum yaw angles of approximately 30° and 20°, respectively, near the ground level were generated in the wind tunnel using a guide vane system, and the test results of wind pressure and wind load in TWFs were compared with those obtained in conventional wind fields (CWFs) with constant wind direction along the vertical axis. In particular, the distribution of extreme cladding pressure as well as the correlation and coherence of local wind loads are discussed in detail. It was observed that the mechanism of the structural dynamic responses, such as the vortex shedding, is greatly affected by TWFs. Both the distributions of mean and extreme cladding pressures in TWFs significantly differ from those in CWFs, especially on the windward and side facades. However, in terms of the amplitudes, the extreme wind pressure and the maximum wind load in TWFs do not noticeably exceed those in CWFs. This study aims to provide useful information for the wind-resistant design of future tall buildings.

The complex wind effects around platform screen doors (PSDs) caused by train-induced piston wind effect and positive micropressure waves in subway station platforms are investigated. Numerical modeling of the wind field around full-scale PSDs with real gaps under different inflow conditions is developed to analyze the pressure distributions on and around the PSDs and the corresponding recirculation regions in the frontal and rear PSD areas with computational fluid dynamics (CFD) method. An equivalent porous media model is developed to obtain the relationship between the pressure difference and wind velocity based on Darcy–Forchheimer’s Law. It includes a viscosity loss term and an inertial loss term in the simulation of the air leakage flow generated from the PSD gap. The coefficients of these two terms are estimated from the CFD results from the full-scale models. The complicated flow field originated from the gaps is the main cause of the large wind pressure on the PSD, and the flow velocity on the platform may significantly affect the comfort of pedestrians and of the safety design of the PSD system.

The microstructures and mechanical properties of the composite extruded AZ31/AZ31 and AZ31/4047 Al sheets were investigated and made a comparison to the conventional extruded AZ31 sheet. Owing to the introduced intense shear deformation at the interface during the composite extrusion, grain refinement and tilted texture were detected in AZ31 layers of the AZ31/AZ31 and AZ31/4047 Al sheets, while the conventional extruded AZ31 sheet exhibited a relative coarse, inhomogeneous microstructure and strong basal texture. The compression-tension yield ratio was increased gradually from the AZ31 to the AZ31/AZ31 and AZ31/4047 Al sheets. Besides, the AZ31/4047 Al sheet could successfully accomplish the whole bending forming process at room temperature, while the AZ31 and AZ31/AZ31 sheets were both bend-formed to failure with significant cracks in the outer tensile region under the identical bending parameters. Moreover, under the same bending strain, both the outward offset degree of strain neutral layer and the sheet thickening were more serious in the AZ31/4047 Al composite sheet than those of the AZ31 and AZ31/AZ31 sheets. The foremost reason was the quite wide gap of material properties between Mg alloy AZ31 layer (tensile loading in the outer region) and Al 4047 layer (compressive loading in the inner region). Keywords: Mg alloy sheet, Composite extrusion, Tension–compression yield asymmetry, Bendability

Remanufacturing is a practice of growing importance due to increasing environmental awareness and regulations. However, the stochastic natures inherent in the remanufacturing processes complicate its scheduling. This paper undertakes the challenge and presents a remanufacturing job shop scheduling approach by integrating alternative routing assignment and machine resource dispatching. A colored timed Petri net is introduced to model the dynamics of remanufacturing process, such as various process routings, uncertain operation times for cores, and machine resource conflicts. With the color attributes in Petri nets, two types of decision points, recovery routing selection and resource dispatching, are introduced and linked with places in CTPN model. With time attributes in Petri nets, the temporal aspect of recovery operations for cores as well as the evolution dynamics in cores' operational stages is mathematically analyzed. A hybrid meta-heuristic algorithm embedded scheduling strategy over CTPN is proposed to search for the optimal recovery routings for worn cores and their recovery operation sequences on workstations, in minimizing the total production cost. The approach is demonstrated through the remanufacturing of used machine tool and its effectiveness is compared against another two cases: baseline case with fixed recovery process routings and case 2 using standard SA/MST.

Composite right/left-handed (CRLH) waveguide leaky-wave antenna (LWA) with low sidelobe level (SLL) and high radiation efficiency is investigated and designed in this paper. Due to the characteristic of negative and positive dominant mode propagation constant of the CRLH transmission line, a backward to forward beam-steering LWA can be realized through frequency scanning. The leaky-wave radiation is analyzed first based on a Ka-band CRLH waveguide with straight slots differently offset on the broadwall. The propagation constant maintains almost invariable as the slot offset varies, meanwhile the attenuation constant has a considerable dynamic range. Thus meandering long slot, whose offset varies along the CRLH waveguide, can be cut on the broadwall to generate a tapered excitation distribution. A prototype of the proposed CRLH waveguide LWA with meandering long slot is designed and fabricated to validate the design. Measurement results show that continuous beam-steering capability from -29° to +31° is achieved, meanwhile the optimized SLLs for the designed antenna patterns are kept below -18.5 dB in the major operating band with the minimum SLL of -22.4 dB at 33 GHz, and the average radiation efficiency is 65.4%. The realized SLLs and radiation efficiency performances of our CRLH LWA surpass others reported in open literatures.

Previous studies show that the largest wind-induced response of a square section fixed-base high-rise building occurs when the strong wind is blowing perpendicular onto a building face, and the greatest translational response is likely to occur in the crosswind direction. When it comes to a square section base-isolated high-rise building that allows the isolation system to yield under strong wind excitation, the inelastic response shows distinctive non-Gaussian characteristics under fluctuating wind excitation and mean drift phenomenon under non-zero mean wind load. These characteristics may lead to a quite different result when determining the most unfavorable wind direction. Thus, the influence of wind direction on the inelastic response of a square base-isolated high-rise building is discussed in this study based on synchronous pressure measurement. The multi-story superstructure is modeled as a linear elastic shear building, while the isolation system is represented in a bilinear hysteresis restoring force model. The peak value of the inelastic response is estimated through a moment-based Hermit model from an underlying standard Gaussian process. The results show that when the strong wind blows perpendicular onto a building face, the greatest inelastic displacement, both at the top and isolation level, occurs in the along-wind direction, which is different from the elastic response. With the change of wind direction, the largest combined inelastic displacement still occurs when the wind inclination angle is 0°, while the combined displacement in other directions is also very large, which is worthy of concern.

This wind tunnel study was conducted to investigate the similarity laws involved in the reasonable simulation of the wake characteristics of a full-scale wind turbine. A 5 MW scaled wind turbine model was designed using an optimization method based on the blade element momentum (BEM) theory. Subsequently, wind tunnel tests were carried out on the geometrically similar model and the thrust-optimized model, with different yaw angles and under various upstream flow conditions. The results indicated that the wake development of the wind turbine model was closely related to the thrust forces of the wind turbine, and both kinematic and dynamic similarity laws should be observed to achieve wake characteristics that are reasonably similar to those of a full-scale wind turbine. This study investigated the aerodynamic similarity principles of small-scale wind turbine models to develop a more effective method for simulating full-scale turbine wake characteristics in wind tunnel tests. The outcomes of this study revealed the limitations of the anomalously low thrust coefficients in geometrically similar wind turbine models and present reasonable model design methodologies for small-scale wind turbine models in wind tunnel tests.

AZ63 sacrificial anode is widely used to protect buried metal pipelines and reinforced concrete structures and so on. The interfacial metallurgical bonding between AZ63 sacrificial anode and Q235 wiring terminal directly affects its cathodic protection performance. Therefore, microstructure and mechanical properties of interfacial between AZ63 and Q235 by solid–liquid compound casting with hot-dip galvanized and post-casting solution-aging treatment (T6) were investigated. The results indicate that hot-dip galvanizing on the surface of Q235 is beneficial to the formation of intermetallic compounds at the interface. At the same time, it can promote the metallurgical bonding of the interface between AZ63 and Q235. After T6 heat treatment, the intermetallic compound at the interface between AZ63 and galvanized Q235 was refined. The electron-probe microanalyzer (EPMA) revealed that the intermetallic compounds at the interfaces between AZ63 and galvanized Q235 were Fe2Al5 before and after T6 treatment. Push-out testing and microhardness were used to investigate the mechanical properties of interface between AZ63 and Q235. It is shown that the hot-dip galvanization of the Q235 surface and T6 treatment were beneficial to improve the metallurgical bonding shear strength and microhardness of the interface. After T6 heat treatment, the highest shear strength at the interface between AZ63 and galvanized Q235 was up to 31.9 ± 1.9 MPa.

This paper compares the parallel-to-grain compressive strengths of wood sample specimens with defects with those of the associated timber log samples. The Chinese fir (Cunninghamia lanceolata) was examined using the static test method. We analyzed the effects of sampling position along the radial direction of the log sample and the age of timber on the parallel-to-grain compressive strength. We then developed time-dependent strength models of the heartwood (HW) and sapwood (SW). These models can be used to evaluate the strength of an aged timber member, using only the service duration, without taking material samples. The degradation of compressive strength over time was then analyzed using an existing multivariate time-dependent model that includes the stress level. The failure strength of the HW was found to be close to that of the SW when at low stress levels. The estimates of the compressive strength of timber members based on these models were better than those recommended by the Chinese National Standard.

With the rapid development of urbanization and the widening gap between urban and rural areas, how to effectively enhance the balanced development of urban and rural areas as well as promote the integrated development of urban and rural areas have become heated topics. Based on the basic theory of urban–rural integration and spatial balance, this paper establishes a comprehensive evaluation system. Using a coupling coordination model and an obstacle degree model, this paper selects 32 indicators from aspects of economy, society and ecology to measure the development level of urban–rural integration in 34 prefecture-level cities in Northeast China from 2000 to 2019. We also analyze the spatial pattern, evolution type characteristics and obstacle factors of urban–rural relations. The results show that: (1) The growth rate of urban development in Northeast China is higher than that of rural development. Except for rural ecology, all dimensions of urban and rural areas have increased year by year, but there are large spatial differences within the region. (2) The urban–rural integration development level of Northeast China is growing constantly and the types of urban and rural coordination are all rising to a higher level. Areas with high urban–rural coordination levels are concentrated in the Harbin–Changchun urban agglomeration and the central and southern Liaoning urban agglomeration, with obvious agglomeration effects. (3) In the coordinated development of urban and rural areas, the restrictive degree of the rural social subsystem was higher than that of the urban subsystem. The restrictive factors in the coordinated development of urban and rural areas are relatively stable, and include per capita consumption expenditure, per capita public budget expenditure, books in public libraries per thousand people, etc. (4) The functions of rural social elements should be enhanced, and the social urban–rural integrated development mechanism should be established to promote the integrated development of urban and rural society.

The study on the fast-growing traits of trees, mainly valued by tree height (TH) and diameter at breast height (DBH), is of great significance to promote the development of the forest industry. Quantitative trait locus (QTL) mapping based on high-density genetic maps is an efficient approach to identify genetic regions for fast-growing traits. In our study, a high-density genetic map for the F1 population was constructed. The genetic map had a total size of 5,484.07 centimorgan (cM), containing 5,956 single nucleotide polymorphisms (SNPs) based on Specific Length Amplified Fragment sequencing. Six fast-growing related stable QTL were identified on six chromosomes, and five stable QTL were identified by a principal component analysis (PCA). By combining the RNA-seq analysis for the two parents and two progenies with the qRT-PCR analysis, four candidate genes, annotated as DnaJ, 1-aminocyclopropane-1-carboxylate oxidase 1 (ACO1), Caffeic acid 3-O-methyltransferase 1 (COMT1), and Dirigent protein 6 (DIR6), that may regulate height growth were identified. Several lignin biosynthesis-related genes that may take part in height growth were detected. In addition, 21 hotspots in this population were found. The results of this study will provide an important foundation for further studies on the molecular and genetic regulation of TH and DBH.

Cost-effective wind energy harvesting by wind turbines in urban areas needs to strengthen the required flow field properties, such as mean velocity, turbulence, and its distribution. This paper conducts a series of CFD simulations to investigate the characteristics and related mechanisms of flow within the cavity, considering the force–turbulence interactions at the RANS scales. The pressure–velocity correlation term is formulated and solved by the elliptic relaxation equation to compensate for the Reynolds stress overestimation. Numerical simulations of flow over an open cavity with the proposed model are compared with corresponding PIV data. The results show that the mean velocity and the fluctuation velocity along the streamwise direction exist a slightly favorable pressure gradient. While the fluctuation velocity and fluctuation pressure show different correlation characteristics along the streamwise direction. Moreover, the pressure–velocity fluctuation correlation becomes obvious near the upper corner of the cavity due to the favorable pressure gradient. Hence, the leading and trailing locations of the cavity are both obvious favorable regions and further emphasis should be put on both high-accurate simulation methods and practical applications.

Cumulative damage and residual deformation of structural components of Yingxian Wood Pagoda over its existence have caused widespread concern. Because Yingxian Wood Pagoda is a very complex ancient wooden structure, previous studies on single-storey and multistorey ancient structures are not very applicable. In this study, the deformation to the pagoda at the components, storey, and overall structure levels was monitored considering residual deformation, component cracking, and component connection conditions. The effects of different factors were preliminarily identified, including the structural weight, external impacts such as earthquakes and artillery shells, differences in moisture content according to sunlight exposure, and the prevailing wind direction. The study findings are useful in diagnosing the health and causes of deformation of unique buildings such as this in order to develop effective repair and restoration measures.

The deformation behavior and microstructural evolution of twin-roll-casting AZ31 Mg alloy sheets were investigated via hot compression tests at 0°, 5°, and 10° from the normal direction. Compression strains of 5%, 15%, 25%, and 35% were employed at high temperatures of 450°C and 500°C. The flow stress as well as the difference in the flow stress associated with different sampling directions decreased when the temperature was increased. Furthermore, the volume fraction of dynamically recrystallized grains increased with increasing deformation, whereas the average grain size decreased. The DRX grain size and the volume fraction of dynamically recrystallized grains increased with increasing deformation temperature. During ultrahigh temperature compression, the effect of sampling direction on the compression microstructure is relatively small.

Background/Aims: Development of effective therapeutic drugs for Parkinson's disease is in great need. During the progression of Parkinson's disease, Rho-associated protein kinase 2 (ROCK2) is activated to promote neurodegeneration. Hydrogen sulfide (H2S) has a neuroprotective effect during the neural injury of Parkinson's disease. However, the mechanisms that underlie the effects of ROCK2 and H2S remain ill-defined. In the current study, we addressed these questions. Methods: We used a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced mouse subacute model of Parkinson's disease to study the effects of H2S on astrocytic activation in the mouse striatum, on the levels of tyrosine-hydroxylase (TH)-positive neuron loss, on the apomorphine-induced rotational behavior of the mice, and on the changes in ROCK2 and miR-135a-5p expression. Plasmid transfection was applied to modify miR-135a-5p levels in a neuronal cell line HCN-1A. Bioinformatics analysis was performed to predict the relationship between ROCK2 and miR-135a-5p in neuronal cells, and then was confirmed by luciferase reporter assay. Results: H2S alleviated MPTP-induced astrocytic activation in the mouse striatum, alleviated the increases in TH-positive neuron loss, and improved the apomorphine-induced rotational behavior of the mice. H2S significantly attenuated the increases in ROCK2 and the decreases in miR-135a-5p by MPTP. MiR-135a-5p targeted the 3'-UTR of ROCK2 mRNA to inhibit its translation in neuronal cells. Conclusion: MiR-135a-5p-regulated ROCK2 may play a role in the protective effects of hydrogen sulfide against Parkinson's disease.

From the point of view of wind engineering, this paper discusses the wind characteristics of China's south-eastern coast area near the ground based on field measurements. Five three-dimensional (3D) ultrasonic anemometers were installed at different heights on a transmission tower in Xiupu, Fujian province, which is a typical coastal landform in South-east China. These anemometers synchronously collected wind records. The wind data were sorted according to the strong wind criterion. The exponent of the mean wind speed and the turbulence intensity profile are provided based on the power law, and suggestions for code are given. The aerodynamic parameters of turbulence in the atmospheric boundary layer are given and used to evaluate the existing empirical models of 3D fluctuating wind speed, such as turbulence intensity, gust factor, turbulence integral length scale and power spectral densities. The provided results can be used by designers to improve the wind resistance of civil engineering projects in South-east China.

The rolled AZ31 Mg alloy sheets were processed by multi-pass bending (MPB) process at room temperature and followed by annealing treatment. Mechanical properties of the as-received and MPB sheets in annealed conditions were examined based on the concurrent microstructure and texture evolution. The results show that the room temperature ductility of the Mg sheets was improved by multi-pass bending process. Moreover, the (0002) basal texture was drastically weakened. Enhanced the ambient mechanical properties, such as lower yield strength and larger uniform elongation, were fabricated by MPB path due to the weak basal texture. The microstructure and mechanical responses were characterized and discussed.

Interfacial reactions between Mg-40Al and Mg-30Y master alloys were investigated at intervals of 25 °C in the 350–400 °C by using a diffusion couple method. Noticeable reaction layers were formed at the interfaces of the diffusion couples. The concentration profiles of the reaction layers were characterized. The diffusion path of the diffusion couple at 400 °C is constructed on the Mg-Al-Y ternary isothermal temperature phase diagram. The phases of the reaction layer were characterized by X-ray diffraction. The interfacial reaction thermodynamics of diffusion couples were studied. These results indicate that Al2Y is the only new formed intermetallic phase in the reaction layers. The growth constants of the reaction layers were calculated. In the reaction layer II, the integrated interdiffusion coefficients of Al are higher than Y, the diffusion activation energy of Y is higher than that of Al.

In the present work, cross-wavy bending at room temperature was carried out to tailor the microstructure and stretch formability of rolled AZ31 sheets. Wavy bending processing generates profuse {10−12} twins and a tilt basal texture. Subsequent recrystallization annealing causes grain coarsening and enhances the intensity of twin-orientation. The combined use of wavy bending and annealing can maintain high tensile ductility and remarkably enhances the stretch formability of rolled AZ31 sheet. It can be mainly attributed to the non-basal texture in the wavy bent sheet which increases the thinning capability during in-plane tension.

Due to the strong suddenness, large destruction and wide impact, disasters can cause serious property and safety loss to tourists, damage significantly tourism infrastructure, properties and resources. In order to prevent disaster and to better understand future disaster risk evolution, we have built a comprehensive disaster risk evaluation model using selected 17 economic and social indicators from tourist destinations in Jilin Province based on the four-factor theory of natural disaster risk formation. The model was used to assess tourist destination disaster risk in Jilin Province for the period of 2009 - 2014. Using GIS technology, we have developed a tourist destination disaster risk zoning map of 2009 – 2014 for Jilin Province, classified the spatial evolution patterns of tourist destination disaster risk. Results showed that the increases in tourist destination disaster risks in Jilin may be spatially evolved by edge contact, sudden internal elevation, swinging and leaping; the decreases in tourist destination disaster risks may be spatially evolved by edge recession, sudden internal reduction and contiguous reduction. The disaster risk spatial evolution model is of value for the emergency department of Jilin Province to take specific emergency measures according to a particular pattern.

In traditional Chinese timber structures, few tie beams were used between columns, and the column base was placed directly on a stone base. In order to study the hysteretic behavior of such structures, a full-scale model was established. The model size was determined according to the requirements of an eighth grade material system specified in the architectural treatise Ying-zao-fa-shi written during the Song Dynasty. In light of the vertical lift and drop of the test model during horizontal reciprocating motions, the horizontal low-cycle reciprocating loading experiments were conducted using a synchronous loading technique. By analyzing the load-displacement hysteresis curves, envelope curves, deformation capacity, energy dissipation, and change in stiffness under different vertical loads, it is found that the timber frame exhibits obvious signs of self-restoring and favorable plastic deformation capacity. As the horizontal displacement increases, the equivalent viscous damping coefficient generally declines first and then increases. At the same time, the stiffness degrades rapidly first and then decreases slowly. Increasing vertical loading will improve the deformation, energy-dissipation capacity, and stiffness of the timber frame.

Tibetan ancient timber structure has great historical, cultural, artistic, and scientific values. The structural configuration of members such as wall, roof, slab, and timber skeleton with semirigid joints is studied in this paper based on field survey results. The aseismic characteristics of Tibetan ancient timber structure have been summarized and introduced. One of the unique features of the Tibetan ancient timber structure is its special beam-column joint which has a semirigid behavior. Numerical simulations of a typical 3-storey structural unit in the Potala Palace are studied. The acceleration responses of the structure under the action of El-Centro seismic waves are studied. Results show that the arrangement of the joints is helpful for seismic resistance of the structure. Most Tibetan ancient timber structures are suffering from different types of damage to certain extent which is vulnerable to seismic actions. Typical damage problems of the structural components are summarized and the main causes of this damage are analyzed. Different rehabilitation methods that can be implemented are discussed, providing references for maintenance of the structures.

AZ31 Mg alloy sheets were processed by the conventional symmetrical extrusion (CSE) and the asymmetric extrusion (ASE). Progressive-asymmetric extrusion (PASE) and severe strain-asymmetric extrusion (SASE) were employed for ASE processes. The texture at near-surface and mid-layer zones of ASE sheets was diverse penetrating the normal direction (ND). This was attributed to an additional asymmetric shear strain deformation during the ASE process. (0002) basal planes of PASE sheets tilt to the shear deformation direction. Meanwhile, the basal texture intensity of PASE sheets has been weakened compared with one in CSE sheets. Grain refinement and tilted weak basal texture obtained by SASE process dramatically enhances the room temperature strength and plasticity of the extruded AZ31 magnesium alloy sheets. The microstructure and mechanical responses were examined and discussed.