Sensitivity analysis of the vane length and passage width for a radial type swirler employed in a triple swirler configuration

The design of axial or radial swirlers typically governs a number of geometrical parameters that are determined by the desired flow field.In the meantime,the number of unknown parameters increases with the number of concentrically mounted swirlers.The available literature is nonetheless limited,and designers are obligated to increase the number of initial assumptions.In this article,three kinds of triple swirlers are employed and simulations are performed to determine the effect of each parameter on the swirler performance.Based on the correlation provided,overlengthening the radial vane length could result in significant changes in the flow field from the jetlike pattern to a wide swirl-jet angle due to the Coanda effect.Passage width should also have the potential to alter the swirl-jet angle and velocity field at the exit of the swirler.

The Paradigm of Surgical Ellipse Dimensions: Are the Length-to-Width Ratio of 3 to 4 and a Vertex Angle of 30ºCorrect?

Background: It has been postulated that elliptical cutaneous excisions must possess a length-to-width ratio of 3 to 4 and a vertex angle of 30o or less in order to be closed primarily without creating a “dog ear”. These dimensions became axiomatic in cutaneous surgery and have been taught in the apprenticeship model for years. The present article examines the validity of that paradigm. Methods: We collected data from two sources: ellipses described in the literature (57 cases);and elliptical excisions performed at the authors’ outpatient clinic (83 cases). The surgical ellipse lengths, widths, and vertex angles were analyzed, and the data were compared to a mathematical formula used to generate a fusiform ellipse. Results: The length-to-width ratio of 3 - 4 was found to be inconsistent with the recommended vertex angle of 30o. In fact, a length-to-width ratio of 3 - 4 determines a vertex angle of 48o - 63o. A 30o vertex angle is only feasible with long length-to-width ration of about 7.5. Conclusions: The paradigm that surgical ellipses should have a vertex angle of 30o with length-to-width ratio of 3 - 4 is incorrect. Evidence from actual surgical practice and from mathematical formulation shows that either the length-to-width ratio must be larger than 3 - 4 or the vertex angle must be larger than 30 degrees.

Impact of Channel Length and Width for Charge Transportation of Graphene Field Effect Transistor

The effect of channel length and width on the large and small-signal parameters of the graphene field effect transistor have been explored using an analytical approach.In the case of faster saturation as well as extremely high transit frequency,the graphene field effect transistor shows outstanding performance.From the transfer curve,it is observed that there is a positive shift of Dirac point from the voltage of 0.15 V to 0.35 V because of reducing channel length from 440 nm to 20 nm and this curve depicts that graphene shows ambipolar behavior.Besides,it is found that because of widening channel the drain current increases and the maximum current is found approximately 2.4 mA and 6 mA for channel width 2μm and 5μm respectively.Furthermore,an approximate symmetrical capacitance-voltage(C-V)characteristic of the graphene field effect transistor is obtained and the capacitance reduces when the channel length decreases but the capacitance can be increased by raising the channel width.In addition,a high transconductance,that demands high-speed radio frequency(RF)applications,of 6.4 mS at channel length 20 nm and 4.45 mS at channel width 5μm along with a high transit frequency of 3.95 THz have been found that demands high-speed radio frequency applications.

Genetic Analysis of Leaf Length and Leaf Width in Bitter Gourd

[Objectives]To explore the genetic mechanism that leaf length and leaf width in bitter gourd has realistic guiding significance for formulating breeding strategy.[Methods]In this paper,the cross was made between CN19-1 and Thai4-6 and an F2segregation population was constructed.The genetic characteristics of leaf length and leaf width were analyzed by employing the major gene plus polygene mixed genetic model.[Results]The data analysis results demonstrated that the leaf length and leaf width of the F_(2) segregation population showed continuous distribution.The optimum model for leaf length genetic analysis was A-1,the additive effect value of the major gene was 3.1766,the dominant effect value was-3.1766,and the heritability was 74.51%.The optimum model for leaf width genetic analysis was B-1.The additive effect values of 2 pairs of major genes controlling the leaf width were 3.1917 and 0.9623,respectively.The dominant effect values were-1.3135 and-0.3463,respectively.The additive×additive interaction effect was-0.3591,the additive×dominant interaction effect was-0.2570,the dominant×additive interaction effect was 1.9916,the dominant×dominant interaction effect was 1.9686.The heritability of major genes was 96.67%.[Conclusions]This study is expected to provide a theoretical basis for the breeding of bitter gourd.

Effect of Overlap Stress as Well as Tie Beam Length and Width on Settlement of Isolated Footings Using Finite Element

Effects of tie beam length, width and overlap stress on settlement of foundations have been investigated. In this investigation square concrete footings have been used with dimensions (B × B × d) where (d) is footing depth and (B) is footing width (1, 1.5,2 m). Width of tie beam (b) has been taken equal to 0.25, 0.30, 0.40, 0.50 and 0.75 (m). Tie beam length (L) has been taken varying from B till 3B with same footing depth = 0.50 m. Effect of overlap stress on settlement as well as effect of tie beam width and length on settlement has been determined. Also, the efficiency of tie beam length and width has been obtained. An equation is presented to compute the overlap stress zone in case of existing tie beam. It is found that the settlement increases with increasing the length of tie beam which is clear after the effect of the overlap stresses zone. The width of overlap stress zone case of existing tie beam has been found to be equal to (1.6 -1.75) B. The settlement of footings decreases with increasing tie beam width. It is found that the settlement after the effect of the overlap stress zone increases with increasing the length of tie beam.

Accurate Interconnection Length and Routing Channel Width Estimates for FPGAs

We study the problem of the prediction of interconnection dimensions for FPGAs, including estimating interconnection length and channel width. Experimental results show that our estimates are more accurate than those of existing methods.

Identification and validation of major QTL for grain size and weight in bread wheat(Triticum aestivum L.)

Grain size and weight are key components of wheat yield.Exploitation of major underlying quantitative trait loci(QTL)can improve yield potential in wheat breeding.A recombinant inbred line(RIL)population was constructed to detect QTL for thousand-grain weight(TGW),grain length(GL)and grain width(GW)across eight environments.Genomic regions associated with grain size and grain weight were identified on chromosomes 4A and 6A using bulked segregant exome sequencing(BSE-Seq)analysis.After constructing genetic maps,six major QTL detected in at least four individual environments and in best linear unbiased estimator(BLUE)datasets,explained 7.50%-23.45%of the phenotypic variation.Except for QGl.cib-4A,the other five QTL were co-located in two regions,namely QTgw/Gw.cib-4A and QTgw/Gw/Gl.cib-6A.Interactions of these QTL were analyzed.Unlike QTgw/Gw/Gl.cib-6A,QTgw/Gw.cib-4A and QGl.cib-4A had no effect on grain number per spike(GNS).The QTL were validated in a second cross using Kompetitive Allele Specific PCR(KASP)markers.Since QTgw/Gw.cib-4A was probably a novel locus,it and the KASP markers reported here can be used in wheat breeding.TraesCS4A03G0191200 was predicted to be potential candidate gene for QTgw/Gw.cib-4A based on the sequence differences,spatiotemporal expression patterns,gene annotation and haplotype analysis.Our findings will be useful for fine mapping and for marker-assisted selection in wheat grain yield improvement.

The Variables and Invariants in the Evolution of Logic Optical Lithography Process

Photolithography has been a major enabler for the continuous shrink of the semiconductor manufacturing design rules.Throughout the years of the development of the photolithography,many new technologies have been invented and successfully implemented,such as image projection lithography,chemically amplified photoresist,phase shifting mask,optical proximity modeling and correction,etc.From 0.25μm technology to the current 7 nm technology,the linewidth has been shrunk from 250 nm to about 20 nm,or 12.5 times.Although imaging resolution is proportional to the illumination wavelength,with the new technologies,the wavelength has only been shrunk from 248 nm to 134.7 nm(193 nm immersion in water),less than 2 times.Would it mean that the imaging performance has been continuously declining?Or we have yet fully utilized the potential of the photolithography technology?In this paper,we will present a study on the key parameters and process window performance of the image projection photolithography from 0.25μm node to the current 7 nm node.

OsDA1 positively regulates grain width in rice

The size and shape of rice grains influence their yield and commercial value.We investigated the role of OsDA1,a rice homolog of the Arabidopsis DA1 gene,in regulating grain size and shape.OsDA1 was highly expressed in young spikelets and glumes.Its overexpression led to enlarged seeds with increased width and decreased length/width ratio(LWR)and knocking out OsDA1 reduced grain width and increased grain length and LWR.A R310K point mutation in the DA1-like domain is a potential target for breeding for increased grain width and length.OsDA1 interacted with TCP gene-family proteins to regulate grain size and shape.Our findings deepen our understanding of the molecular mechanisms underlying grain size regulation and provide useful information for improving grain yield.

Effect of Calcium Source in Supplemental Diets on the Growth Performance and Carcass Characteristics of the Giant African Land Snails (Archachatina marginata) in the Western Highlands of Cameroon

To contribute to the diversification of protein sources, the conservation and preservation of the Giant African Land Snails (Archachatina marginata), a study was carried out between March and July 2019 at the Helvy Farms-WVED Cameroon located at Station Bamenda to investigate the effect of three calcium sources on their growth performance and carcass characteristics. 180 juvenile snails aged 4 months initially weighing between 24.2 and 28.5 g, shell length ranging between 40.25 - 48.35 mm, and shell diameter of between 14.08 - 18.44 mm were randomly allotted to 3 treatments containing each a different calcium source (crushed snail shell, eggshell and agricultural limestone) and a control treatment constituted of natural plant feeding materials of the snail. There were 45 snails per treatment, constituted of three replicates with 15 snails per replicate. Each replicate was housed in well-constructed surface trench pens equipped with drinking and feeding troughs. The basal diet made up of feedstuffs like pawpaw leaves and watermelons was provided ad libitum. The initial weights of the snails were recorded at the start of the experiment followed by weekly weight measurements, while the snail length and width were measured with a digital caliper of 0.05 mm accuracy. The snails were monitored for a period of 21 weeks and data was collected for 20 weeks after a 1 week adaptation period. The results showed that the weight gain (g) of snails for diets containing calcium sources in the supplemental diets were all significantly higher (P < 0.05) than the corresponding values recorded for the control diet with natural plant material. It was observed that the shell length (0.34 ± 0.02), shell width (0.16 ± 0.02), weight gain (13.13 ± 0.03) and feed conversion efficiency (1.977 ± 0.11) were highest in snails fed snail shell diet as calcium source compared with snails from other treatments. These values were however not significantly higher than corresponding values for the other two supplemental diets containing eggshell or agricultural limestone. It can be deduced that the snail shell is an important calcium source for growing snails and can be adopted and used in the diets of snails. This will amount to some good methods of recycling in snail production.

Allometric models for leaf area and leaf mass predictions across different growing seasons of elm tree(Ulmus japonica)

Convenient and effective methods to determine seasonal changes in individual leaf area (LA) and leaf mass (LM) of plants are useful in research on plant physiology and forest ecology. However, practical methods for estimating LA and LM of elm (Ulmus japonica) leaves in different periods have rarely been reported. We collected sample elm leaves in June, July and September. Then, we developed allometric models relating LA, LM and leaf parameters, such as leaf length (L) and width (W) or the product of L and W (LW). Our objective was to find optimal allometric models for conveniently and effectively estimating LA and LM of elm leaves in different periods. LA and LM were significantly correlated with leaf parameters (P < 0.05), and allometric models with LW as an independent variable were best for estimating LA and LM in each period. A linear model was separately developed to predict LA of elm leaves in June, July and September, and it yielded high accuracies of 93, 96 and 96%, respectively. Similarly, a specific allometric model for predicting LM was developed separately in three periods, and the optimal model form in both June and July was a power model, but the linear model was optimal for September. The accuracies of the allometric models in predicting LM were 88, 83 and 84% for June, July and September, respectively. The error caused by ignoring seasonal variation of allometric models in predicting LA and LM in the three periods were 1-4 and 16-59%, respectively.

Influence of epitaxial layer structure and cell structure on electrical performance of 6.5 kV SiC MOSFET

Silicon carbide(SiC)material features a wide bandgap and high critical breakdown field intensity.It also plays an important role in the high efficiency and miniaturization of power electronic equipment.It is an ideal choice for new power electronic devices,especially in smart grids and high-speed trains.In the medium and high voltage fields,SiC devices with a blocking voltage of more than 6.5 kV will have a wide range of applications.In this paper,we study the influence of epitaxial material properties on the static characteristics of 6.5 kV SiC MOSFET.6.5 kV SiC MOSFETs with different channel lengths and JFET region widths are manufactured on three wafers and analyzed.The FN tunneling of gate oxide,HTGB and HTRB tests are performed and provide data support for the industrialization process for medium/high voltage SiC MOSFETs.

基于Mask RCNN和视觉技术的玉米种子发芽自动检测方法

种子标准发芽试验中,为获取种子发芽和生长情况,需借助人工定时对种子的发芽率、发芽势、芽长和根长等相关指标进行统计和测量,该测定过程费时费力,且易对发芽的幼苗造成损伤。针对这些问题,该研究基于Mask RCNN(基于区域的卷积神经网络)模型和机器视觉技术设计了一种玉米种子发芽自动检测方法。首先,在玉米种子发芽试验的7 d内,每天采集模型训练和测试所需的图像,并用Labelme工具对种子位置进行标注,再利用标注图像训练种子定位模型;其次,根据模型定位出的玉米种子掩膜区域,设定一个监测种子发芽的椭圆区域,自动识别种子发芽状态;最后,利用骨架提取和深度搜索算法实现发芽种子幼苗主骨架线的提取,通过计算种子掩膜的质心坐标位置,实现芽和根长度的分别统计。结果表明,该方法能够有效识别发芽种子,实现发芽试验中玉米种子的发芽率、发芽势、芽长、根长等指标的自动统计,可为种子发芽试验的自动化管理提供技术参考。

Design Criteria for Crosswalk Width and Position at Signalized Intersections

Existing optimization methodologies for intersection operations assumes a fixed geometric design, however the geometry and operational system should be simultaneously optimized to produce the best performance. Signalized crosswalks are complex and critical pedestrian facilities. Their geometry and configuration directly affect the safety, cycle length and resulting delays for all users. As crosswalks become wider or they are placed further upstream, the cycle length will increase due to the all-red time requirement, which deteriorates the overall mobility levels of signalized intersections. In contrast, when crosswalk width decreases, the required minimum pedestrian crossing time increases due to the bi-directional pedestrian flow effects, which leads to longer cycle length. Furthermore, existing manuals and guidelines do not offer any specification for the required crosswalk width under various pedestrian demand conditions. This study aims to propose new criteria for designing crosswalk width at signalized intersections, which can optimize the performance from the viewpoint of vehicular traffic and pedestrians. The proposed methodology considers pedestrian demand and its characteristics （such as bi-directional flow effects）, vehicle demand and the geometric characteristics of the intersection The concept of optimized crosswalk width is proposed and demonstrated through a case study. Moreover, a comprehensive discussion regarding the merits and drawbacks of existing strategies on positioning crosswalks is presented. It was found that at signalized intersections, which are characterized by low pedestrian and high vehicle demands, crosswalk width of 2 meters is appropriate to minimize cycle length and resulting delays for all users including pedestrians.

Comparative Analysis of Technical Parameters of Different Knitted Structures (Jersey, Pique and Lacoste) with or without Lycra/Spandex

The relationship of Count, GSM (Gram per Square meter), and Stitch Length, Shrinkage%, spirality% and pilling are discussed by this paper among Pique, Lacoste and Jersey knit structures with or without Lycra “3% - 5%”. For this research, we used different knitted structures, yarn count and stitch length and for finding data different types of m/c are used which are discussed later. This study is based on finish GSM of Pique, Lacoste and Jersey Knit Fabrics where various kinds of yarn count, GSM and Stitch length are used to justify the experiment. The relation of count and Stitch length with GSM is inversely proportional. When count and Stitch length increases, GSM decreases which is proved through this paper by using both the expected and experimental data. For writing this paper we have distinguished both the theoretical as well as practical implications from the industry and tried to find out adjustable points of fabrics Count, GSM and Stitch Length along with Shrinkage%, Fabric width, Spirality. This paper provides a reliable result which will help selection of count, GSM and Stitch length for making of Pique, Lacoste and Jersey knit fabrics with or without Lycra maintaining the Shrinkage%, spirality%, pilling grade in an acceptable limit. This paper logically shows that GSM, shrinkage and spirality vary when structure, yarn count, and stitch length vary.

不同叶长·叶宽和单叶重对广元烤后烟叶质量的影响

为明确广元优质烤后烟叶适宜的叶长、叶宽和单叶重范围,为广元地区生产优质烤烟提供数据支撑,2021年在四川省广元市剑阁县5个收购线分别挑选10户种植水平具有代表性的烟农,取X2F、C2F、C3F和B2F等级烟叶样品各2 kg,按等级划分不同叶长、叶宽和单叶重进行烟叶质量评价。结果表明:随着叶长的增加,X2F、B2F等级烟叶总糖、还原糖含量呈减少趋势。随着叶长的增加,C3F烟叶烟碱、钾含量升高;随着叶宽的增加,C3F烟叶总糖、还原糖含量逐渐增加。X2F和C3F等级烟叶随着单叶重的增加,总糖含量逐渐增加,钾含量减少。随着烟叶叶宽和单叶重的增加,X2F烟叶外观质量总分均表现为先增加后降低。随着叶长的增加,C2F和C3F烟叶外观质量总分均表现为逐渐增加,外观质量总分从高到低依次为>75 cm、>65~75 cm、>55~65 cm、≤55 cm。随着叶长、叶宽和单叶重的增加,C2F、C3F、B2F烟叶感官质量得分大多表现为先上升后下降。随着叶长、叶宽的增加,C2F、B2F烟叶感官质量得分表现为先上升后下降。当X2F烟叶叶长控制在>50~60 cm、叶宽控制在>15~19 cm、单叶重控制在>7~11 g时,X2F烟叶综合品质较好;当C2F烟叶叶长控制在>55~65 cm、叶宽控制在>15~23 cm、单叶重控制在>9~13 g时,C2F烟叶综合品质较好;当C3F烟叶叶长控制在>65~75 cm、叶宽控制在>15~23 cm、单叶重控制在>8~12 g时,C3F烟叶综合品质较好;当B2F叶长控制在>55~65 cm、叶宽控制在>15~23 cm、单叶重控制在>9~15 g时,B2F烟叶综合品质较好。

基于长度可变密钥的光学图像加密方法

为提升光学图像加密效果,设计了一种基于长度可变密钥的光学图像加密方法。基于混沌方程构成混沌序列均匀化普适算法,运用该算法生成均匀化伪随机序列,以此作为长度可变密钥,经空间光调制器调制后,转换此类密钥为伪随机相位掩模(PRPM),运用两个转换后PRPM双重随机相位编码初始光学图像,并结合变形分数傅里叶变换(AFrFT),相位转换编码后光学图像,获得加密光学图像,完成光学图像加密。实验结果显示,该方法可针对不同光学图像生成敏感性与唯一性密钥,实现不同光学图像的加密处理,加密效果显著,加密光学图像的像素频数分布均匀,且解密后光学图像与初始光学图像几乎一致,整体加解密效果理想,可有效保障光学图像的安全性,而且本方法可以在最短3 s的时间内完成光学图像的加密和解密,加解密效率更高,综合效果更佳。

非纯弯作用下I形波板组合梁的弹性屈曲应力

纯弯条件下,带钢翼缘板的波形钢腹板I形组合梁(简称I形波板梁)的屈曲应力已有明确的计算公式,但该公式不适用于非纯弯的条件。笔者对自由端受集中荷载的悬臂式I形波板梁进行了数值模拟研究,结果表明:该种梁有3种屈曲模态,分别是翼缘板屈曲、波板屈曲和耦合屈曲;当梁的屈曲由翼缘板屈曲主导时,悬臂式非纯弯梁的屈曲应力大于纯弯梁的屈曲应力,此时翼缘板的宽长比为影响翼缘板屈曲应力的主要因子;结合大量的数值模拟结果,笔者对翼缘板屈曲系数进行了修正,提出了涵盖全部屈曲模式的I形波板梁屈曲应力计算公式。

空间整形飞秒激光高效制备纳米光栅

针对常规物镜聚焦飞秒激光光斑较小,难以单次直写加工成型大面积纳米光栅结构的问题,提出了利用空间狭缝整形的飞秒激光脉冲直写方法。通过开展单晶硅表面纳米光栅结构对加工系统的参数依赖关系研究,获得入射整形飞秒激光能量密度8.00μJ/cm^(2)、扫描速度9 mm/s、狭缝宽度0.40 mm的优化条件。采用SEM、AFM等手段对光栅进行微观表征,结果表明,单次扫描所制备的纳米光栅结构具有极高的宽度(41.20μm),说明提出的方法可以显著提升一次成型大面积纳米光栅结构的制备效率。

基于55K芯片小麦籽粒相关性状的QTL定位分析

为了进一步挖掘小麦籽粒相关性状的主效QTL位点,探索籽粒性状之间的遗传关系,利用籽粒性状差异较大的小麦品种安农859和武农988构建的124份DH群体为研究材料,分别测定2 a 7个环境下的粒长、粒宽及千粒质量表型值,开展籽粒性状多元回归分析,并基于DH群体的55K芯片数据进行籽粒相关性状QTL检测。结果表明,多元回归分析中,粒宽对千粒质量的贡献最大。通过完备区间作图对籽粒性状进行QTL定位,除6D和7B染色体外,其他19条染色体上共检测到69个有关籽粒性状的QTL,包括24个千粒质量QTL、28个粒长QTL、17个粒宽QTL,单个QTL的表型解释率为6.87%~27.74%。其中,7A染色体上粒长相关的Qgl.ahau-7A.1在7个环境及BLUP下均被检测到,表型解释率为9.48%~22.26%,加性效应为0.11~0.21 mm,物理区间4.91 Mb(AX-110430243~AX-110442528),可能为新的主效QTL。因此,Qgl.ahau-7A.1位点可作为后续精细定位和分子标记辅助育种重点关注的区域。