Morphological characteristics and gene mapping of a dense panicle (dp2) mutant in rice (Oryza sativa L.)

Yunlong Yang,Chunhai Shi,Yuanfei Zhou,Jianguo Wu,Xiaoli Jin,Jianyao Shou 한국유전학회 2014 Genes & Genomics Vol.36 No.3

A dense panicle mutant (dp2) derived from theOryza sativa ssp. japonica cultivar Nipponbare through ethylmethane sulfonate mutagenesis was used in present study. Compared to the wild type, the panicle of dp2 mutantexhibited more branches and denser grains. Further more, thenumber of spikelets per panicle, number of primary branchesand secondary branches of dp2 mutant were significantlyincreased while the panicle length, and 1,000-grain weightwere significantly decreased. The results from the geneticanalysis indicated that the dense panicle phenotype wascontrolled by a single dominance nuclear gene. Polymorphicanalysis of SSR and InDel markers demonstrated that theDP2 gene was located at the long arm of chromosome 2,which was further mapped between SSR markers RM341and RM13356 in a physical region of 398 kb. Within thisregion, the RCN2 (LOC_Os02g32950) gene which wasannotated relating to the development of rice panicle wasfound. Compared to the wild type, the sequence of RCN2gene in the dp2 mutant showed that two SNPs replacementhad taken place in the promoter region (G–A) and the intronregion (A–T), respectively. The dp2 mutant could be a novelmutant of RCN2 gene and this novel mutant might be usefulfor further studies on this gene.

Seismic performance of RC columns with full resistance spot welding stirrups

Yunlong Yu,Zhaohui Dang,Yong Yang,Yang Chen,Hui Li 국제구조공학회 2020 Structural Engineering and Mechanics, An Int'l Jou Vol.73 No.5

This paper aims to investigate the seismic performance of RC short columns and long columns with welding stirrups. Through the low-cyclic horizontal loading test of specimens, the seismic performance indexes such as failure modes, hysteretic curve, skeleton curve, ductility, energy dissipation capacity, stiffness degradation and strength degradation were emphatically analyzed. Furthermore, the effects of shear span ratio, stirrups ratio and axial compression ratio on the performance of specimens were studied. The results showed that the seismic performance of the RC short columns with welding stirrups were basically the same as that of the RC short columns with traditional stirrups, but the seismic performance of RC long columns with welding stirrups was better than that of RC long columns with traditional stirrups. The seismic performance of RC short columns and long columns with welding stirrups could be improved by increasing stirrup ratio and shear span ratio and reducing axial pressure ratio. Moreover, the welding stirrup have the advantages of steel saving, industrialization and standardization production, convenient construction, and reducing time, which indicated that the welding stirrups could be applied in practical engineering.

Seismic performance of RC columns with encased prefabricated high-strength CFST core

Yong Yang,Dongde Sun,Yicong Xue,Yunlong Yu,Kang An,Yang Chen 국제구조공학회 2021 Steel and Composite Structures, An International J Vol.39 No.6

This paper proposed an innovative RC column with encased prefabricated high-strength concrete filled steel tube core, and four RC columns with encased prefabricated high-strength CFST core and a RC control-column were tested under lateral low cyclic loading. All specimens were evaluated by the cracks developments, failure patterns, hysteretic behavior, skeleton curves, strength and stiffness degradation, ductility and energy dissipation capacity. The effects of stirrup ratio and welding studs of prefabricated CFST core were investigated in details. The experiment results indicated that compared with the RC control-column, the performances of RC columns with encased prefabricated high-strength CFST core, including the hysteretic behavior, strength degradation, ductility and energy dissipation, were significantly improved. Higher stirrup ratio of the RC column with encased prefabricated high-strength CFST core leaded to higher ductility and more satisfactory energy dissipation capacity, stiffness degradation. Studs could effectively combine prefabricated high-strength CFST core and surrounding concrete, which significantly increase the integrity of RC column with encased prefabricated high-strength CFST core. Based on the test results, a numerical model was established to further analyze the cyclic behavior of the test specimens, and the numerical results agreed well with the test results, which showed the feasibility for the further parametric study. Finally, on the basis of the plastic stress theory, a calculation model for seismic bending moment capacity of RC column with encased prefabricated high-strength CFST core was established, and the results obtained form the formulas showed good agreement with the experiments.

Experimental investigation on shear capacity of partially prefabricated steel reinforced concrete columns

Yong Yang,Yang Chen,Jintao Zhang,Yicong Xue,Ru-yue Liu,Yunlong Yu 국제구조공학회 2018 Steel and Composite Structures, An International J Vol.28 No.1

This paper experimentally and analytically elucidates the shear behavior and shear bearing capacity of partially prefabricated steel reinforced concrete (PPSRC) columns and hollow partially prefabricated steel reinforced concrete (HPSRC) columns. Seven specimens including five PPSRC column specimens and two HPSRC column specimens were tested under static monotonic loading. In the test, the influences of shear span aspect ratio and difference of cast-in-place concrete strength on the shear behavior of PPSRC and HPSRC columns were investigated. Based on the test results, the failure pattern, the loaddisplacement behavior and the shear capacity were focused and analyzed. The test results demonstrated that all the column specimens failed in shear failure mode with high bearing capacity and good deformability. Smaller shear span aspect ratio and higher strength of inner concrete resulted in higher shear bearing capacity, with more ductile and better deformability. Furthermore, calculation formula for predicting the ultimate shear capacity of the PPSRC and HPSRC columns were proposed on the basis of the experimental results.

Cyclic tests on RC joints retrofitted with pre-stressed steel strips and bonded steel plates

Yunlong Yu,Yong Yang,Yicong Xue,Niannian Wang,Yaping Liu 국제구조공학회 2020 Structural Engineering and Mechanics, An Int'l Jou Vol.75 No.6

An innovative retrofit method using pre-stressed steel strips and externally-bonded steel plates was presented in this paper. With the aim of exploring the seismic performance of the retrofitted RC interior joints, four 1/2-scale retrofitted joint specimens together with one control specimen were designed and subjected to constant axial compression and cyclic loading, with the main test parameters being the volume of steel strips and the existence of externally-bonded steel plates. The damage mechanism, force-displacement hysteretic response, force-displacement envelop curve, energy dissipation and displacement ductility ratio were analyzed to investigate the cyclic behavior of the retrofitted joints. The test results indicated that all the test specimens suffered a typical shear failure at the joint core, and the application of externally-bonded steel plates and that of pre-stressed steel strips could effectively increase the lateral capacity and deformability of the deficient RC interior joints, respectively. The best cyclic behavior could be found in the deficient RC interior joint retrofitted using both externally-bonded steel plates and pre-stressed steel strips due to the increased lateral capacity, displacement ductility and energy dissipation. Finally, based on the test results and the softened strut and tie model, a theoretical model for determining the shear capacity of the retrofitted specimens was proposed and validated.

Angle-sensitive Pixels Based on Subwavelength Compound Gratings

Yunlong Meng,Xuemei Hu,Cheng Yang,Xinyu Shen,Xueyun Cao,Lankun Lin,Feng Yan,Tao Yue 한국광학회 2022 Current Optics and Photonics Vol.6 No.4

In this paper, we present a new design for angle-sensitive pixels (ASPs). The proposed ASPs take advantage of subwavelength compound gratings to capture the light angle, which enables pixel size to reach the wavelength scale of 0.7 μm × 0.7 μm. The subwavelength compound gratings are implement-ed by the wires of the readout circuit inherent to the standard complementary metal–oxide–semiconductor manufacturing process, thus avoiding additional off-chip optics or post-processing. This technique allows the use of two pixels for horizontal or vertical angle detection, and can determine the light’s angle in the range from −45° to +45°. The proposed sensor enables surface-profile reconstruction of mi-croscale samples using a lensless imaging system.

Research on a Spectral Reconstruction Method with Noise Tolerance

Yunlong Ye,Jianqi Zhang,Delian Liu,Yixin Yang 한국광학회 2021 Current Optics and Photonics Vol.5 No.5

As a new type of spectrometer, that based on filters with different transmittance features attracts a lot of attention for its advantages such as small-size, low cost, and simple optical structure. It uses post-processing algorithms to achieve target spectrum reconstruction; therefore, the performance of the spectrometer is severely affected by noise. The influence of noise on the spectral reconstruction results is studied in this paper, and suggestions for solving the spectral reconstruction problem under noisy conditions are given. We first list different spectral reconstruction methods, and through simulations demonstrate that these methods show unsatisfactory performance under noisy conditions. Then we propose to apply the gradient projection for sparse reconstruction (GRSR) algorithm to the spectral reconstruction method. Simulation results show that the proposed method can significantly reduce the influence of noise on the spectral reconstruction process. Meanwhile, the accuracy of the spectral reconstruction results is dramatically improved. Therefore, the practicality of the filter-based spectrometer will be enhanced.

Shear behavior and shear capacity prediction of precast concrete-encased steel beams

Yunlong Yu,Yong Yang,Yicong Xue,Yaping Liu 국제구조공학회 2020 Steel and Composite Structures, An International J Vol.36 No.3

A novel precast concrete-encased steel composite beam, which can be abbreviated as PCES beam, is introduced in this paper. In order to investigate the shear behavior of this PCES beam, a test of eight full-scale PCES beam specimens was carried out, in which the specimens were subjected to positive bending moment or negative bending moment, respectively. The factors which affected the shear behavior, such as the shear span-to-depth aspect ratio and the existence of concrete flange, were taken into account. During the test, the load-deflection curves of the test specimens were recorded, while the crack propagation patterns together with the failure patterns were observed as well. From the test results, it could be concluded that the tested PCES beams could all exhibit ductile shear behavior, and the innovative shear connectors between the precast concrete and cast-in-place concrete, namely the precast concrete transverse diaphragms, were verified to be effective. Then, based on the shear deformation compatibility, a theoretical model for predicting the shear capacity of the proposed PCES beams was put forward and verified to be valid with the good agreement of the shear capacities calculated using the proposed method and those from the experiments. Finally, in order to facilitate the preliminary design in practical applications, a simplified calculation method for predicting the shear capacity of the proposed PCES beams was also put forward and validated using available test results.

Study on mechanical performance of composite beam with innovative composite slabs

Yunlong Yu,Yong Yang,Xianwei Zhou,Charles W. Roeder,Xudong Huo 국제구조공학회 2016 Steel and Composite Structures, An International J Vol.21 No.3

A new type of composite beam which consists of a wide flange steel shape beam and an innovative type of composite slab was introduced. The composite slab is composed of concrete slab and normal flat steel plates, which are connected by perfobond shear connectors (PBL shear connectors). This paper describes experiments of two large-scale specimens of that composite beam. Both specimens were loaded at two symmetric points for 4-point loading status, and mechanical behaviors under hogging and sagging bending moments were investigated respectively. During the experiments, the crack patterns, failure modes, failure mechanism and ultimate bending capacity of composite beam specimens were investigated, and the strains of concrete and flat steel plate as well as steel shapes were measured and recorded. As shown from the experimental results, composite actions were fully developed between the steel shape and the composite slab, this new type of composite beams was found to have good mechanical performance both under hogging and sagging bending moment with high bending capacity, substantial flexure rigidity and good ductility. It was further shown that the plane-section assumption was verified. Moreover, a design procedure including calculation methods of bending capacity of this new type of composite beam was studied and proposed based on the experimental results, and the calculation methods based on the plane-section assumption and plastic theories were also verified by comparisons of the calculated results and experimental results, which were agreed with each other.

Shear behavior of concrete-encased square concrete-filled steel tube members: Experiments and strength prediction

Yong Yang,Xin Chen,Yicong Xue,Yunlong Yu,Chaorui Zhang 국제구조공학회 2021 Steel and Composite Structures, An International J Vol.38 No.4

This paper presents experiments and theoretical analysis on shear behavior of eight concrete-encased square concrete-filled steel tube (CECFST) specimens and three traditional reinforced concrete (RC) specimens. A total of 11 specimens with the test parameters including the shear span-to-depth ratio, steel tube size and studs arrangement were tested to explore the shear performance of CECFST specimens. The failure mode, shear capacity and displacement ductility were thoroughly evaluated. The test results indicated that all the test specimens failed in shear, and the CECFST specimens enhanced by the interior CFST core exhibited higher shear capacity and better ductility performance than that of the RC specimens. When the other parameters were the same, the larger steel tube size, the smaller shear span-to-depth ratio and the existence of studs could lead to the more satisfactory shear behavior. Then, based on the compatible truss-arch model, a set of formulas were developed to analytically predict the shear strength of the CECFST members by considering the compatibility of deformation between the truss part, arch part and the steel tube. Compared with the calculated results based on several current design specifications, the proposed formulas could get more accurate prediction.