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A genome-wide association study (GWAS) was applied to detect single nucleotide polymorphisms (SNPs) significantly associated with resistance to Heterodera glycines (HG) also known as the soybean cyst nematode (SCN) in the core collection of common bean, Phaseolus vulgaris. There were 84,416 SNPs identified in 363 common bean accessions. GWAS identified SNPs on chromosome (Chr) 1 that were significantly associated with resistance to HG type 2.5.7. These SNPs were in linkage disequilibrium with a gene cluster orthologous to the three genes at the Rhg1 locus in soybean. A novel signal on Chr 7 was detected and associated with resistance to HG type 1.2.3.5.6.7. Genomic predictions (GPs) for resistance to these two SCN HG types in common bean achieved prediction accuracy of 0.52 and 0.41, respectively. Our study generated a high-quality SNP panel for 363 common bean accessions and demonstrated that both GWAS and GP were effective strategies to understand the genetic architecture of SCN resistance in common bean.

To explore the effect of the photoperiod on the accumulation and distribution of dry matter in potato, a pot experiment was carried out in 2021 and 2022 with two varieties (Atlantic and Hezuo 88). The varieties were used as the main plot, and light treatments (short-day and long-day) were used as the subplot. The results showed that extended hours of light delayed tuber formation in Hezuo 88, however, the effect was not obvious for the Atlantic. Comprehensive analyses were carried out using the potato developmental process, dynamic equation fitting of the tuber and whole-plant dry matter accumulation, and the dry matter accumulation and distribution rate of each organ of the two varieties under two photoperiods. The two photoperiods had different effects on the parameters of rapid tuber and whole-plant dry matter accumulation: the starting point of the period of the rapid dry matter accumulation (t1), the duration period of the rapid dry matter accumulation (Δt), and the average growth rate of the period of the rapid dry matter accumulation (Vmean). According to comprehensive analysis, tuber dry matter accumulation in Atlantic was the highest under the short-day condition, while Hezuo 88 showed the lowest tuber dry matter accumulation under the long-day condition and was the latest to enter the rapid tuber dry matter accumulation period. The whole-plant dry matter accumulation in Atlantic was the highest under the long-day condition and lowest in Hezuo 88; meanwhile, Hezuo 88 was the latest to enter the rapid whole-plant dry matter accumulation period. In terms of the dry matter accumulation and dry matter partitioning ratio of various organs, Hezuo 88 had the lowest mean tuber dry matter accumulation and partitioning ratio under the long-day condition but the highest mean stem, leaf, root, underground stem, and stolon dry matter partitioning ratio. On the contrary, Atlantic had the highest mean tuber dry matter accumulation and portioning ratio under the short-day condition but the lowest mean stem, leaf, root, underground stem, and stolon dry matter partitioning ratio. It was concluded that different varieties of potato respond differently to the photoperiod. In the case of Hezuo 88, prolonging the photoperiod affected the dynamics and distribution of dry matter accumulation; increased the stem, leaf, root, and underground stem dry matter partitioning ratio; and decreased the tuber dry matter partitioning ratio, which resulted in a decrease in tuber dry matter accumulation and consequently delayed the emergence of the equilibrium period between the aboveground and underground dry matter. [ABSTRACT FROM AUTHOR]

Due to the black and glossy appearance of the carbon fiber prepreg bundle surface, the accurate identification of surface defects in automated fiber placement (AFP) presents a high level of difficulty. Currently, the enhanced YOLOv7 algorithm demonstrates certain performance advantages in this detection task, yet issues with missed detections, false alarms, and low confidence levels persist. Therefore, this study proposes an improved YOLOv7 algorithm to further enhance the performance and generalization of surface defect detection in AFP. Firstly, to enhance the model's feature extraction capability, the BiFormer attention mechanism is introduced to make the model pay more attention to small target defects, thereby improving feature discriminability. Next, the AFPN structure is used to replace the PAFPN at the neck layer to strengthen feature fusion, preserve semantic information to a greater extent, and finely integrate multi-scale features. Finally, WIoU is adopted to replace CIoU as the bounding box regression loss function, making it more sensitive to small targets, enabling more accurate prediction of object bounding boxes, and enhancing the model's detection accuracy and generalization capability. Through a series of ablation experiments, the improved YOLOv7 shows a 10.5% increase in mAP and a 14 FPS increase in frame rate, with a maximum detection speed of 35 m/min during the AFP process, meeting the requirements of online detection and thus being able to be applied to surface defect detection in AFP operations. [ABSTRACT FROM AUTHOR]

In this work, a novel approach involving coating fine PEEK powder on prepreg is introduced to improve wedge peel strength and reduce interlaminar voids. CF/PEEK laminates with resin interleaving are in situ consolidated by laser-assisted fiber placement. The morphology of the powdered surface is obtained using an optical profilometer, and the surface roughness and volume of added resin are calculated accordingly. Interface and surface temperature are measured during the layup process. Thermal history indicates that very short bonding time is the dominating factor for voids and limited interlayer strength. Laminate porosity and microscopic features are characterized with an optical microscope. The porosity of resin-interleaved laminates decreases to 3.7%, while the resin content only increases by 4.5% in the meantime. This is because interlayer resin particles rapidly melt under laser heating and quickly fill the voids between layers. The wedge peel strength of resin-interleaved laminates can increase by 30.1% without a repass treatment. This could be attributed to the increase in resin intimate contact and reduction in interlayer voids. [ABSTRACT FROM AUTHOR]

In order to ensure the performance of the automated fiber placement forming parts, according to the homogeneity of the image of the prepreg surface along the fiber direction, a defect segmentation algorithm which was the combination of gray compensation and substraction algorithm based on image processing technology was proposed. The gray compensation matrix of image was used to compensate the gray image, and the maximum error point of the image matrix was eliminated according to the characteristics that the gray error obeys the normal distribution. The standard image was established, using the allowed deviation coefficient K as a criterion for substraction segmentation. Experiments show that the algorithm has good effect, fast speed in segmenting two kinds of typical laying defect of bubbles or foreign objects, and provides a good theoretical basis to realize automatic laying defect online monitoring.

Natural ventilation is one of the most important passive strategies for optimizing building energy saving and environmental performance. However, it is difficult for natural ventilation design to realize the utmost utilization of ambient energy based on the conventional design process due to the design performance of natural ventilation is significantly influenced by the schematic plan of a building. Therefore, this study introduces a design process using a concise model of Thermal Autonomy as an evaluation metric for the early design stage. To apply the proposed metric to modern office buildings, which are equipped with effective HVAC systems, a practical and common thermal comfort criterion of 21°C–27°C is adopted to replace the adaptive comfort standard in the original Thermal Autonomy quantification. The availability of the proposed metric for rapid diagnosis is evaluated through parametric simulation based on a typical office building in Shanghai. The evaluation result and the visual map of Thermal Autonomy are verified to determine the proper air change rate and to help architects to understand the design performance of their natural ventilation scheme. In the case study, the proper air change rate is estimated at 8 ac/h corresponding to a comfort hour of 1314 h. This comfort hour value accounts for the maximum value of 50% during the occupied hour. In addition, the effect of Thermal Autonomy in decision-making regarding envelope insulation and initial operation conditions is examined. It is beneficial to maintain the indoor thermal environment by setting the lower outdoor temperature limit for opening windows at 17°C under a higher feasible ventilation volume. A relatively high envelope insulation level with 50 mm or 75 mm insulation layer is advantageous for improving Thermal Autonomy under a larger ventilation volume condition. The method proposed in this study is practical for objectively evaluating the design performance of natural ventilation during the early design stage. [ABSTRACT FROM AUTHOR]

Natural ventilation is an essential component in sustainable building design. However, successfully incorporating it remains difficult because the utilizable amounts of ambient energy resources differ according to project conditions such as ambient climates. Moreover, lack of a metric that could encourage an architect to design a proper plan and façade for natural ventilation at the schematic design stage is being recognized as a barrier to successful achievement of natural ventilation. An inappropriate plan and façade would make it impossible to make thorough considerations for successful implementation of natural ventilation at the later design stages. To encourage even the architects without special expertise in natural ventilation, the metric should be as simple as possible to evaluate the achieved natural ventilation design intuitively and rationally. This paper proposes net Thermal Autonomy as a modified metric of Thermal Autonomy, which cannot easily evaluate the achievement level because the applied weather data significantly influence the calculated value. In the proposed metric, a universal threshold covering climate factors is available by applying net time, while the outdoor condition suitable for natural ventilation is used in the denominator. The practicality of the proposed metric is examined through parametric building energy simulations and analyses.

The concept of cutting platform is proposed and realized based on the latest two-step automated tape laying (Two-step ATL)technology, which separates prepreg cutting process from tape laying to improve productivity for large parts with small features. Two-step ATL is more efficient than conventional layup because ply patches are pre-cut in a separate operation. The concept of the prepreg tape cutting experimental platform with two cutters is introduced. Further, based on the automatic tape laying trajectory planning software, a two-cutter cutting algorithm is proposed. Cutting experiments are reported to validate both the concept of cutting platform and cutting algorithm. [ABSTRACT FROM AUTHOR]

We investigated the magnetic and ferroelectric properties of orthochromite SmCrO3 by using density functional theory simulations. The atom coordinates of both Pbnm and Pna21 were calculated, and Pna21 was found to be the ground state structure. The spontaneous polarization in Pna21 structure is sensitive to delicate structure change which is induced by different antiferromagnetic order, and its direction is along the c axis. The spin structure of Pbnm was analyzed and it was found to not support ferroelectricity. The results revealed the origin of ferroelectricity of multiferroic SmCrO3 and explained the magnetoelectric effect. [ABSTRACT FROM AUTHOR]

We investigated the magnetic and ferroelectric properties of orthochromite SmCrO3 by using density functional theory simulations. The atom coordinates of both Pbnm and Pna21 were calculated, and Pna21 was found to be the ground state structure. The spontaneous polarization in Pna21 structure is sensitive to delicate structure change which is induced by different antiferromagnetic order, and its direction is along the c axis. The spin structure of Pbnm was analyzed and it was found to not support ferroelectricity. The results revealed the origin of ferroelectricity of multiferroic SmCrO3 and explained the magnetoelectric effect. [ABSTRACT FROM AUTHOR]

As a three-dimensional layer enhancement technology, Z-pin technology is suitable for manufacturing composite prepreg laminates and also can effectively improve inter laminar properties of composite laminates. In order to manufacture Z-pin cylindrical and conical shape composite parts efficiently, an ultrasonic assistant insertion system is proposed, and the general plan is worked out to meet all the technical requirements of ultrasonic transfer insertion automation. The prototype machine is designed, a series of function debugging are made and verification experiments are carried out on the machine. The results show that the system meets all technical requirements of ultrasonic assistant insertion process. It is capable to carry out ultrasonic assistant insertion automatically, as a result, the system is much more efficient than the existing equipment as much as 6 times. [ABSTRACT FROM AUTHOR]